Common Core: High School - Geometry : Use Distance Formula to Compute and Compare Perimeters and Areas of Polygons: CCSS.Math.Content.HSG-GPE.B.7

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Example Questions

Example Question #73 : Expressing Geometric Properties With Equations

Find the perimeter of the following polygon with the points \(\displaystyle (10, 14)\), \(\displaystyle (7, -20)\), \(\displaystyle ( 1, 8)\) and \(\displaystyle (1, -15)\) to two decimal places.

 

Possible Answers:

\(\displaystyle P = 389.4\)

\(\displaystyle P = 106.1\)

\(\displaystyle P = 116.1\)

\(\displaystyle P = 117.1\)

\(\displaystyle P = 88.8\)

Correct answer:

\(\displaystyle P = 116.1\)

Explanation:

In order to find the perimeter, we need to find the sum of the edges of the polygon.

In order to do this, we need to find the distance between the points.

Let's recall the distance formula.

\(\displaystyle D = \sqrt{\left(x_{0} - x_{1}\right)^{2} + \left(y_{0} - y_{1}\right)^{2}}\)

Lets say that

\(\displaystyle \\p_{1} = \left ( 10, \quad 14\right ) \\p_{2} = \left ( 7, \quad -20\right ) \\p_{3} = \left ( 1, \quad 8\right ) \\p_{4} = \left ( 1, \quad -15\right )\)

Here is a picture of the polygon

Plot1

Let's first find the distance between \(\displaystyle p_{1}\) and \(\displaystyle p_{2}\)

\(\displaystyle \\D = \sqrt{\left(10 - 7\right)^{2} + \left(14- - 20\right)^{2}} \\D=\sqrt{\left(3\right)^{2} + \left(34\right)^{2}} \\D=\sqrt{9 + 1156}\)

\(\displaystyle D{\left (p_{1},p_{2} \right )} = \sqrt{1165}\)

Now let's find the distance between \(\displaystyle p_{2}\) and \(\displaystyle p_{3}\)

\(\displaystyle \\D = \sqrt{\left(7 - 1\right)^{2} + \left(-20 - 8\right)^{2}} \\D=\sqrt{\left(6\right)^{2} + \left(-28\right)^{2}} \\D=\sqrt{36 + 784}\\D=\sqrt{820}\)

\(\displaystyle D{\left (p_{2},p_{3} \right )} = 2 \sqrt{205}\)

Now let's find the distance between \(\displaystyle p_{3}\) and \(\displaystyle p_{4}\)

\(\displaystyle \\D = \sqrt{\left(1 - 1\right)^{2} + \left(8- - 15\right)^{2}} \\D=\sqrt{\left(0\right)^{2} + \left(23\right)^{2}} \\D=\sqrt{0 + 529}\)

\(\displaystyle D{\left (p_{3},p_{4} \right )} = 23\)

Now let's find the distance between \(\displaystyle p_{4}\) and \(\displaystyle p_{1}\)

\(\displaystyle \\D = \sqrt{\left(1 - 10\right)^{2} + \left(-15 - 14\right)^{2}} \\D=\sqrt{\left(-9\right)^{2} + \left(-29\right)^{2}} \\D=\sqrt{81 + 841}\)

\(\displaystyle D{\left (p_{4},p_{1} \right )} = \sqrt{922}\)

Now since we have the distances, we can simply sum up each edge to get the perimeter.

\(\displaystyle \\P = 23 + 2 \sqrt{205} + \sqrt{922} + \sqrt{1165} \\P = 116.1\)

 

Example Question #74 : Expressing Geometric Properties With Equations

Find the perimeter of the following polygon with the points \(\displaystyle (0, 12)\), \(\displaystyle (1, 4)\), \(\displaystyle (-14, -4)\) and \(\displaystyle (-1, -19)\) to two decimal places.

 

Possible Answers:

\(\displaystyle P = 75.93\)

\(\displaystyle P = 65.93\)

\(\displaystyle P = 355.1\)

\(\displaystyle P = 76.93\)

\(\displaystyle P = 48.01\)

Correct answer:

\(\displaystyle P = 75.93\)

Explanation:

In order to find the perimeter, we need to find the sum of the edges of the polygon.

In order to do this, we need to find the distance between the points.

Let's recall the distance formula.

\(\displaystyle D = \sqrt{\left(x_{0} - x_{1}\right)^{2} + \left(y_{0} - y_{1}\right)^{2}}\)

Lets say that 

\(\displaystyle \\p_{1} = \left ( 0, \quad 12\right ) \\p_{2} = \left ( 1, \quad 4\right ) \\p_{3} = \left ( -14, \quad -4\right ) \\ p_{4} = \left ( -1, \quad -19\right )\)

Here is a picture of the polygon

Plot2

Let's first find the distance between \(\displaystyle p_{1}\) and \(\displaystyle p_{2}\)

\(\displaystyle \\D = \sqrt{(0) - 1)^{2} + \left(12 - 4\right)^{2}} \\D=\sqrt{1+ \left(8\right)^{2}} \\D=\sqrt{1+64}\)

\(\displaystyle D{\left (p_{1},p_{2} \right )} = \sqrt{65}\)

Now let's find the distance between \(\displaystyle p_{2}\) and \(\displaystyle p_{3}\)

\(\displaystyle \\D = \sqrt{(1) --14)^{2} + \left(4- - 4\right)^{2}} \\D=\sqrt{15^2+ \left(8\right)^{2}} \\D=\sqrt{225+64}\\D=\sqrt{289}\)

\(\displaystyle D{\left (p_{2},p_{3} \right )} = 17\)

Now let's find the distance between \(\displaystyle p_{3}\) and \(\displaystyle p_{4}\)

\(\displaystyle \\D = \sqrt{(-14) -- 1)^{2} + \left(-4 - -19\right)^{2}} \\D=\sqrt{(-13)^2+ \left(15\right)^{2}} \\D=\sqrt{169+225}\)

\(\displaystyle D{\left (p_{3},p_{4} \right )} = \sqrt{394}\)

Now let's find the distance between \(\displaystyle p_{4}\) and \(\displaystyle p_{1}\)

\(\displaystyle \\D = \sqrt{(-1) - 0)^{2} + \left(-19 - 12\right)^{2}} \\D=\sqrt{1+ \left(-31\right)^{2}} \\D=\sqrt{1+961}\)

\(\displaystyle D{\left (p_{4},p_{1} \right )} = \sqrt{962}\)

Now since we have the distances, we can simply sum up each edge to get the perimeter.

\(\displaystyle \\P = \sqrt{65} + 17 + \sqrt{394} + \sqrt{962} \\P = 75.93\)

 

Example Question #75 : Expressing Geometric Properties With Equations

Find the perimeter of the following polygon with the points \(\displaystyle (8, 13)\), \(\displaystyle (5, -18)\), \(\displaystyle (-6, -6)\), and \(\displaystyle (-2, -5)\) to two decimal places.

 

 

Possible Answers:

\(\displaystyle P = 72.14\)

\(\displaystyle P = 53.61\)

\(\displaystyle P = 257.5\)

\(\displaystyle P = 73.14\)

\(\displaystyle P = 62.14\)

Correct answer:

\(\displaystyle P = 72.14\)

Explanation:

In order to find the perimeter, we need to find the sum of the edges of the polygon.

In order to do this, we need to find the distance between the points.

Let's recall the distance formula.

\(\displaystyle D = \sqrt{\left(x_{0} - x_{1}\right)^{2} + \left(y_{0} - y_{1}\right)^{2}}\)

Lets say that

\(\displaystyle \\p_{1} = \left ( 8, \quad 13\right ) \\p_{2} = \left ( 5, \quad -18\right ) \\p_{3} = \left ( -6, \quad -6\right ) \\p_{4} = \left ( -2, \quad -5\right )\)

Here is a picture of the polygon

Plot3

Let's first find the distance between \(\displaystyle p_{1}\) and \(\displaystyle p_{2}\)

\(\displaystyle \\D = \sqrt{\left(8 - 5\right)^{2} + \left(13- - 18\right)^{2}} \\D=\sqrt{\left(3\right)^{2} + \left(31\right)^{2}} \\D=\sqrt{9+ 961}\)

\(\displaystyle D{\left (p_{1},p_{2} \right )} = \sqrt{970}\)

Now let's find the distance between \(\displaystyle p_{2}\) and \(\displaystyle p_{3}\)

\(\displaystyle \\D = \sqrt{\left(5- -6\right)^{2} + \left(-18- - 6\right)^{2}} \\D=\sqrt{\left(11\right)^{2} + \left(-12\right)^{2}} \\D=\sqrt{121+144}\)

\(\displaystyle D{\left (p_{2},p_{3} \right )} = \sqrt{265}\)

Now let's find the distance between \(\displaystyle p_{3}\) and \(\displaystyle p_{4}\)

\(\displaystyle \\D = \sqrt{\left(-6- -2\right)^{2} + \left(-6- - 5\right)^{2}} \\D=\sqrt{\left(-4\right)^{2} + \left(-1\right)^{2}} \\D=\sqrt{16+1}\)

\(\displaystyle D{\left (p_{3},p_{4} \right )} = \sqrt{17}\)

Now let's find the distance between \(\displaystyle p_{4}\) and \(\displaystyle p_{1}\)

\(\displaystyle \\D = \sqrt{\left(-2- 8\right)^{2} + \left(-5- 13\right)^{2}} \\D=\sqrt{\left(-10\right)^{2} + \left(-18\right)^{2}} \\D=\sqrt{100+324}\\D=\sqrt{424}\)

\(\displaystyle D{\left (p_{4},p_{1} \right )} = 2 \sqrt{106}\)

Now since we have the distances, we can simply sum up each edge to get the perimeter.

\(\displaystyle \\P = \sqrt{17} + \sqrt{265} + 2 \sqrt{106} + \sqrt{970} \\P = 72.14\)

 

Example Question #76 : Expressing Geometric Properties With Equations

Find the perimeter of the following polygon with the points \(\displaystyle (8, 10)\), \(\displaystyle (-7, -8)\), \(\displaystyle (-18, -10)\), and \(\displaystyle (-1, -14)\) to two decimal places.

Possible Answers:

\(\displaystyle P = 77.71\)

\(\displaystyle P = 54.64\)

\(\displaystyle P = 308.4\)

\(\displaystyle P = 67.71\)

\(\displaystyle P = 78.71\)

Correct answer:

\(\displaystyle P = 77.71\)

Explanation:

In order to find the perimeter, we need to find the sum of the edges of the polygon.

In order to do this, we need to find the distance between the points.

Let's recall the distance formula.

\(\displaystyle D = \sqrt{\left(x_{0} - x_{1}\right)^{2} + \left(y_{0} - y_{1}\right)^{2}}\)

Lets say that 

\(\displaystyle \\p_{1} = \left ( 8, \quad 10\right ) \\p_{2} = \left ( -7, \quad -8\right ) \\p_{3} = \left ( -18, \quad -10\right ) \\ p_{4} = \left ( -1, \quad -14\right )\)

Here is a picture of the polygon

Plot4

Let's first find the distance between \(\displaystyle p_{1}\) and \(\displaystyle p_{2}\)

\(\displaystyle \\D = \sqrt{\left(8 - -7\right)^{2} + \left(10- - 8\right)^{2}} \\D= \sqrt{\left(15\right)^{2} + \left(18\right)^{2}} \\D=\sqrt{225+324}\)

\(\displaystyle D{\left (p_{1},p_{2} \right )} = 3 \sqrt{61}\)

Now let's find the distance between \(\displaystyle p_{2}\) and \(\displaystyle p_{3}\)

\(\displaystyle \\D = \sqrt{\left( -7--18\right)^{2} + \left(- 8--10\right)^{2}} \\D= \sqrt{\left(11\right)^{2} + \left(2\right)^{2}} \\D=\sqrt{121+4}\)

\(\displaystyle D{\left (p_{2},p_{3} \right )} = 5 \sqrt{5}\)

Now let's find the distance between \(\displaystyle p_{3}\) and \(\displaystyle p_{4}\)

\(\displaystyle \\D = \sqrt{\left( -18--1\right)^{2} + \left(-10--14\right)^{2}} \\D= \sqrt{\left(-17\right)^{2} + \left(4\right)^{2}} \\D=\sqrt{289+16}\)

\(\displaystyle D{\left (p_{3},p_{4} \right )} = \sqrt{305}\)

Now let's find the distance between \(\displaystyle p_{4}\) and \(\displaystyle p_{1}\)

\(\displaystyle \\D = \sqrt{\left( -1-8\right)^{2} + \left(-14-10\right)^{2}} \\D= \sqrt{\left(-9\right)^{2} + \left(-24\right)^{2}} \\D=\sqrt{81+576}\)

\(\displaystyle D{\left (p_{4},p_{1} \right )} = 3 \sqrt{73}\)

Now since we have the distances, we can simply sum up each edge to get the perimeter.

\(\displaystyle \\P = 5 \sqrt{5} + \sqrt{305} + 3 \sqrt{61} + 3 \sqrt{73} \\P = 77.71\)

 

Example Question #5 : Use Distance Formula To Compute And Compare Perimeters And Areas Of Polygons: Ccss.Math.Content.Hsg Gpe.B.7

Find the perimeter of the following polygon with the points \(\displaystyle (-4, 11)\), \(\displaystyle (-12, -12)\), \(\displaystyle (4, 7)\), and \(\displaystyle (1, 9)\) to two decimal places.

 

Possible Answers:

\(\displaystyle P = 58.18\)

\(\displaystyle P = 48.18\)

\(\displaystyle P = 53.33\)

\(\displaystyle P = 106.6\)

\(\displaystyle P = 59.18\)

Correct answer:

\(\displaystyle P = 58.18\)

Explanation:

In order to find the perimeter, we need to find the sum of the edges of the polygon.

In order to do this, we need to find the distance between the points.

Let's recall the distance formula.

\(\displaystyle D = \sqrt{\left(x_{0} - x_{1}\right)^{2} + \left(y_{0} - y_{1}\right)^{2}}\)

Lets say that 

\(\displaystyle \\p_{1} = \left ( -4, \quad 11\right )\\ p_{2} = \left ( -12, \quad -12\right ) \\p_{3} = \left ( 4, \quad 7\right ) \\ p_{4} = \left ( 1, \quad 9\right )\)

Here is a picture of the polygon

Plot5

Let's first find the distance between \(\displaystyle p_{1}\) and \(\displaystyle p_{2}\)

\(\displaystyle \\D = \sqrt{\left(-4- -12\right)^{2} + \left(11- - 12\right)^{2}} \\D = \sqrt{\left(8)^{2} + \left(23\right)^{2}}\)

\(\displaystyle \\D = \sqrt{64 + 529}\)

\(\displaystyle D{\left (p_{1},p_{2} \right )} = \sqrt{593}\)

Now let's find the distance between \(\displaystyle p_{2}\) and \(\displaystyle p_{3}\)

\(\displaystyle \\D = \sqrt{\left(-12-4\right)^{2} + \left(- 12-7\right)^{2}} \\D = \sqrt{\left(-16)^{2} + \left(-19\right)^{2}}\)

\(\displaystyle \\D = \sqrt{256 + 361}\)

\(\displaystyle D{\left (p_{2},p_{3} \right )} = \sqrt{617}\)

Now let's find the distance between \(\displaystyle p_{3}\) and \(\displaystyle p_{4}\)

\(\displaystyle \\D = \sqrt{\left(4-1\right)^{2} + \left(7-9\right)^{2}} \\D = \sqrt{\left(3)^{2} + \left(-2\right)^{2}}\)

\(\displaystyle \\D = \sqrt{9 + 4}\)

\(\displaystyle D{\left (p_{3},p_{4} \right )} = \sqrt{13}\)

Now let's find the distance between \(\displaystyle p_{4}\) and \(\displaystyle p_{1}\)

\(\displaystyle \\D = \sqrt{\left(1--4\right)^{2} + \left(9-11\right)^{2}} \\D = \sqrt{\left(5)^{2} + \left(-2\right)^{2}}\)

\(\displaystyle \\D = \sqrt{25 + 4}\)

\(\displaystyle D{\left (p_{4},p_{1} \right )} = \sqrt{29}\)

Now since we have the distances, we can simply sum up each edge to get the perimeter.

\(\displaystyle \\P = \sqrt{13} + \sqrt{29} + \sqrt{593} + \sqrt{617} \\P = 58.18\)

 

Example Question #6 : Use Distance Formula To Compute And Compare Perimeters And Areas Of Polygons: Ccss.Math.Content.Hsg Gpe.B.7

Find the perimeter of the following polygon with the points \(\displaystyle (0, -7)\), \(\displaystyle (-6, -2)\), \(\displaystyle (-5, -5)\), and \(\displaystyle (-1, 1)\) to two decimal places.

 

 

Possible Answers:

\(\displaystyle P = 18.99\)

\(\displaystyle P = 27.25\)

\(\displaystyle P = 26.25\)

\(\displaystyle P = 16.25\)

\(\displaystyle P = 98.81\)

Correct answer:

\(\displaystyle P = 26.25\)

Explanation:

In order to find the perimeter, we need to find the sum of the edges of the polygon.

In order to do this, we need to find the distance between the points.

Let's recall the distance formula.

\(\displaystyle D = \sqrt{\left(x_{0} - x_{1}\right)^{2} + \left(y_{0} - y_{1}\right)^{2}}\)

Lets say that

\(\displaystyle \\p_{1} = \left ( 0, \quad -7\right )\\ p_{2} = \left ( -6, \quad -2\right ) \\p_{3} = \left ( -5, \quad -5\right ) \\ p_{4} = \left ( -1, \quad 1\right )\)

Here is a picture of the polygon

Plot6

Let's first find the distance between \(\displaystyle p_{1}\) and \(\displaystyle p_{2}\)

\(\displaystyle \\D = \sqrt{\left(0--6\right)^{2} + \left(-7--2}\right)^{2}} \\D = \sqrt{\left(6\right)^{2} + \left(-5}\right)^{2}} \\D = \sqrt{36 + 25}\)

\(\displaystyle D{\left (p_{1},p_{2} \right )} = \sqrt{61}\)

Now let's find the distance between \(\displaystyle p_{2}\) and \(\displaystyle p_{3}\)

\(\displaystyle \\D = \sqrt{\left(-6--5\right)^{2} + \left(-2--5}\right)^{2}} \\D = \sqrt{\left(-1\right)^{2} + \left(3}\right)^{2}} \\D = \sqrt{1 + 9}\)

\(\displaystyle D{\left (p_{2},p_{3} \right )} = \sqrt{10}\)

Now let's find the distance between \(\displaystyle p_{3}\) and \(\displaystyle p_{4}\)

\(\displaystyle \\D = \sqrt{\left(-5--1\right)^{2} + \left(-5-1}\right)^{2}} \\D = \sqrt{\left(-4\right)^{2} + \left(-6}\right)^{2}} \\D = \sqrt{16 + 36}\)

\(\displaystyle D{\left (p_{3},p_{4} \right )} = 2 \sqrt{13}\)

Now let's find the distance between \(\displaystyle p_{4}\) and \(\displaystyle p_{1}\)

\(\displaystyle \\D = \sqrt{\left(-1-0\right)^{2} + \left(1--7}\right)^{2}} \\D = \sqrt{\left(-1\right)^{2} + \left(8}\right)^{2}} \\D = \sqrt{1 + 64}\)

\(\displaystyle D{\left (p_{4},p_{1} \right )} = \sqrt{65}\)

Now since we have the distances, we can simply sum up each edge to get the perimeter.

\(\displaystyle \\P = \sqrt{10} + 2 \sqrt{13} + \sqrt{61} + \sqrt{65} \\P = 26.25\)

Example Question #7 : Use Distance Formula To Compute And Compare Perimeters And Areas Of Polygons: Ccss.Math.Content.Hsg Gpe.B.7

Find the perimeter of the following polygon with the points \(\displaystyle (-7, 12)\), \(\displaystyle (9, 7)\), \(\displaystyle (-14, 5)\), and \(\displaystyle (1, 9)\) to two decimal places.

 

Possible Answers:

\(\displaystyle P = 63.92\)

\(\displaystyle P = 140.8\)

\(\displaystyle P = 56.23\)

\(\displaystyle P = 53.92\)

\(\displaystyle P = 64.92\)

Correct answer:

\(\displaystyle P = 63.92\)

Explanation:

In order to find the perimeter, we need to find the sum of the edges of the polygon.

In order to do this, we need to find the distance between the points.

Let's recall the distance formula.

\(\displaystyle D = \sqrt{\left(x_{0} - x_{1}\right)^{2} + \left(y_{0} - y_{1}\right)^{2}}\)

Lets say that 

\(\displaystyle \\p_{1} = \left ( -7, \quad 12\right ) \\p_{2} = \left ( 9, \quad 7\right ) \\p_{3} = \left ( -14, \quad 5\right ) \\ p_{4} = \left ( 1, \quad 9\right )\)

Here is a picture of the polygon

Plot7

Let's first find the distance between \(\displaystyle p_{1}\) and \(\displaystyle p_{2}\)

\(\displaystyle \\D = \sqrt{\left(-7 - 9\right)^{2} + \left(12 - 7\right)^{2}} \\D= \sqrt{\left(-16\right)^{2} + \left(5\right)^{2}} \\D= \sqrt{256 + 25}\)

\(\displaystyle D{\left (p_{1},p_{2} \right )} = \sqrt{281}\)

Now let's find the distance between \(\displaystyle p_{2}\) and \(\displaystyle p_{3}\)

\(\displaystyle \\D = \sqrt{\left( 9--14\right)^{2} + \left( 7-5\right)^{2}} \\D= \sqrt{\left(23\right)^{2} + \left(2\right)^{2}} \\D= \sqrt{529 + 4}\)

\(\displaystyle D{\left (p_{2},p_{3} \right )} = \sqrt{533}\)

Now let's find the distance between \(\displaystyle p_{3}\) and \(\displaystyle p_{4}\)

\(\displaystyle \\D = \sqrt{\left( -14-1\right)^{2} + \left( 5-9\right)^{2}} \\D= \sqrt{\left(-15\right)^{2} + \left(-4\right)^{2}} \\D= \sqrt{225 + 16}\)

\(\displaystyle D{\left (p_{3},p_{4} \right )} = \sqrt{241}\)

Now let's find the distance between \(\displaystyle p_{4}\) and \(\displaystyle p_{1}\)

\(\displaystyle \\D = \sqrt{\left( 1--7\right)^{2} + \left( 9-12\right)^{2}} \\D= \sqrt{\left(8\right)^{2} + \left(-3\right)^{2}} \\D= \sqrt{64 + 9}\)

\(\displaystyle D{\left (p_{4},p_{1} \right )} = \sqrt{73}\)

Now since we have the distances, we can simply sum up each edge to get the perimeter.

\(\displaystyle \\P = \sqrt{73} + \sqrt{241} + \sqrt{281} + \sqrt{533} \\P = 63.92\)

 

Example Question #8 : Use Distance Formula To Compute And Compare Perimeters And Areas Of Polygons: Ccss.Math.Content.Hsg Gpe.B.7

Find the perimeter of the following polygon with the points \(\displaystyle (2, 1)\), \(\displaystyle (19, -7)\), \(\displaystyle (11, 11)\), and \(\displaystyle (4, 8)\) to two decimal places.

Possible Answers:

\(\displaystyle P = 46.83\)

\(\displaystyle P = 43.38\)

\(\displaystyle P = 54.38\)

\(\displaystyle P = 118.9\)

\(\displaystyle P = 53.38\)

Correct answer:

\(\displaystyle P = 53.38\)

Explanation:

In order to find the perimeter, we need to find the sum of the edges of the polygon.

In order to do this, we need to find the distance between the points.

Let's recall the distance formula.

\(\displaystyle D = \sqrt{\left(x_{0} - x_{1}\right)^{2} + \left(y_{0} - y_{1}\right)^{2}}\)

Lets say that 

\(\displaystyle \\p_{1} = \left ( 2, \quad 1\right ) \\p_{2} = \left ( 19, \quad -7\right ) \\p_{3} = \left ( 11, \quad 11\right ) \\ p_{4} = \left ( 4, \quad 8\right )\)

Here is a picture of the polygon

Plot8

Let's first find the distance between \(\displaystyle p_{1}\) and \(\displaystyle p_{2}\)

\(\displaystyle \\D = \sqrt{\left(2 - 19\right)^{2} + \left(1- - 7\right)^{2}} \\D= \sqrt{\left(-17\right)^{2} + \left(8\right)^{2}} \\D= \sqrt{289 + 64}\)

\(\displaystyle D{\left (p_{1},p_{2} \right )} = \sqrt{353}\)

Now let's find the distance between \(\displaystyle p_{2}\) and \(\displaystyle p_{3}\)

\(\displaystyle \\D = \sqrt{\left( 19-11\right)^{2} + \left( -7-11\right)^{2}} \\D= \sqrt{\left(8\right)^{2} + \left(-18\right)^{2}} \\D= \sqrt{64 + 324}\\D=\sqrt{388}\)

\(\displaystyle D{\left (p_{2},p_{3} \right )} = 2 \sqrt{97}\)

Now let's find the distance between \(\displaystyle p_{3}\) and \(\displaystyle p_{4}\)

\(\displaystyle \\D = \sqrt{\left( 11-4\right)^{2} + \left( 11-8\right)^{2}} \\D= \sqrt{\left(7\right)^{2} + \left(3\right)^{2}} \\D= \sqrt{49+ 9}\)

\(\displaystyle D{\left (p_{3},p_{4} \right )} = \sqrt{58}\)

Now let's find the distance between \(\displaystyle p_{4}\) and \(\displaystyle p_{1}\)

\(\displaystyle \\D = \sqrt{\left( 4-2\right)^{2} + \left( 8-1\right)^{2}} \\D= \sqrt{\left(2\right)^{2} + \left(7\right)^{2}} \\D= \sqrt{4 + 49}\)

\(\displaystyle D{\left (p_{4},p_{1} \right )} = \sqrt{53}\)

Now since we have the distances, we can simply sum up each edge to get the perimeter.

\(\displaystyle \\P = \sqrt{53} + \sqrt{58} + \sqrt{353} + 2 \sqrt{97} \\P = 53.38\)

 

Example Question #9 : Use Distance Formula To Compute And Compare Perimeters And Areas Of Polygons: Ccss.Math.Content.Hsg Gpe.B.7

Find the perimeter of the following polygon with the points \(\displaystyle (-9, -10)\), \(\displaystyle (0, -19)\), \(\displaystyle (11, -6)\), and \(\displaystyle (0, -6)\) to two decimal places.

Possible Answers:

\(\displaystyle P = 50.61\)

\(\displaystyle P = 40.61\)

\(\displaystyle P = 139.2\)

\(\displaystyle P = 51.61\)

\(\displaystyle P = 41.74\)

Correct answer:

\(\displaystyle P = 50.61\)

Explanation:

In order to find the perimeter, we need to find the sum of the edges of the polygon.

In order to do this, we need to find the distance between the points.

Let's recall the distance formula.

\(\displaystyle D = \sqrt{\left(x_{0} - x_{1}\right)^{2} + \left(y_{0} - y_{1}\right)^{2}}\)

Lets say that

\(\displaystyle \\p_{1} = \left ( -9, \quad -10\right ) \\p_{2} = \left ( 0, \quad -19\right ) \\p_{3} = \left ( 11, \quad -6\right ) \\ p_{4} = \left ( 0, \quad -6\right )\)

Here is a picture of the polygon

Plot9

Let's first find the distance between \(\displaystyle p_{1}\) and \(\displaystyle p_{2}\)

\(\displaystyle \\D = \sqrt{\left(-9 - 0\right)^{2} + \left(-10--19\right)^{2}} \\D=\sqrt{\left(-9\right)^{2} + \left(9\right)^{2}} \\D=\sqrt{81 + 81}\)

\(\displaystyle D{\left (p_{1},p_{2} \right )} = 9 \sqrt{2}\)

Now let's find the distance between \(\displaystyle p_{2}\) and \(\displaystyle p_{3}\)

\(\displaystyle \\D = \sqrt{\left(0-11\right)^{2} + \left(-19--6\right)^{2}} \\D=\sqrt{\left(-11\right)^{2} + \left(-13\right)^{2}} \\D=\sqrt{121 + 169}\)

\(\displaystyle D{\left (p_{2},p_{3} \right )} = \sqrt{290}\)

Now let's find the distance between \(\displaystyle p_{3}\) and \(\displaystyle p_{4}\)

\(\displaystyle \\D = \sqrt{\left(11-0\right)^{2} + \left(-6--6\right)^{2}} \\D=\sqrt{\left(11\right)^{2} + \left(0\right)^{2}} \\D=\sqrt{121 + 0}\)

\(\displaystyle D{\left (p_{3},p_{4} \right )} = 11\)

Now let's find the distance between \(\displaystyle p_{4}\) and \(\displaystyle p_{1}\)

\(\displaystyle \\D = \sqrt{\left(0--9\right)^{2} + \left(-6--10\right)^{2}} \\D=\sqrt{\left(9\right)^{2} + \left(4\right)^{2}} \\D=\sqrt{81 + 16}\)

\(\displaystyle D{\left (p_{4},p_{1} \right )} = \sqrt{97}\)

Now since we have the distances, we can simply sum up each edge to get the perimeter.

\(\displaystyle \\P = \sqrt{97} + 11 + 9 \sqrt{2} + \sqrt{290} \\P = 50.61\)

 

Example Question #10 : Use Distance Formula To Compute And Compare Perimeters And Areas Of Polygons: Ccss.Math.Content.Hsg Gpe.B.7

Find the perimeter of the following polygon with the points \(\displaystyle (-1, 13)\), \(\displaystyle (-3, -2)\), \(\displaystyle (1, -7)\), and \(\displaystyle (-2, -9)\) to two decimal places.

 

Possible Answers:

\(\displaystyle P = 245.4\)

\(\displaystyle P = 37.16\)

\(\displaystyle P = 48.16\)

\(\displaystyle P = 47.16\)

\(\displaystyle P = 27.34\)

Correct answer:

\(\displaystyle P = 47.16\)

Explanation:

In order to find the perimeter, we need to find the sum of the edges of the polygon.

In order to do this, we need to find the distance between the points.

Let's recall the distance formula.

\(\displaystyle D = \sqrt{\left(x_{0} - x_{1}\right)^{2} + \left(y_{0} - y_{1}\right)^{2}}\)

Lets say that

\(\displaystyle \\p_{1} = \left ( -1, \quad 13\right ) \\p_{2} = \left ( -3, \quad -2\right ) \\p_{3} = \left ( 1, \quad -7\right ) \\ p_{4} = \left ( -2, \quad -9\right )\)

Here is a picture of the polygon

 Plot10

Let's first find the distance between \(\displaystyle p_{1}\) and \(\displaystyle p_{2}\)

\(\displaystyle \\D = \sqrt{\left(-1--3\right)^{2} + \left(13--2\right)^{2}} \\D=\sqrt{\left(2\right)^{2} + \left(15\right)^{2}} \\D=\sqrt{4+225 }\)

\(\displaystyle D{\left (p_{1},p_{2} \right )} = \sqrt{229}\)

Now let's find the distance between \(\displaystyle p_{2}\) and \(\displaystyle p_{3}\)

\(\displaystyle \\D = \sqrt{\left(-3-1\right)^{2} + \left(-2--7\right)^{2}} \\D=\sqrt{\left(-4\right)^{2} + \left(5\right)^{2}} \\D=\sqrt{16+25}\)

\(\displaystyle D{\left (p_{2},p_{3} \right )} = \sqrt{41}\)

Now let's find the distance between \(\displaystyle p_{3}\) and \(\displaystyle p_{4}\)

\(\displaystyle \\D = \sqrt{\left(1--2\right)^{2} + \left(-7--9\right)^{2}} \\D=\sqrt{\left(3\right)^{2} + \left(2\right)^{2}} \\D=\sqrt{9+4 }\)

\(\displaystyle D{\left (p_{3},p_{4} \right )} = \sqrt{13}\)

Now let's find the distance between \(\displaystyle p_{4}\) and \(\displaystyle p_{1}\)

\(\displaystyle \\D = \sqrt{\left(-2--1\right)^{2} + \left(-9-13\right)^{2}} \\D=\sqrt{\left(-1\right)^{2} + \left(-22\right)^{2}} \\D=\sqrt{1+484 }\)

\(\displaystyle D{\left (p_{4},p_{1} \right )} = \sqrt{485}\)

Now since we have the distances, we can simply sum up each edge to get the perimeter.

\(\displaystyle \\P = \sqrt{13} + \sqrt{41} + \sqrt{229} + \sqrt{485} \\P = 47.16\)

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