Intermediate Geometry : Lines

Study concepts, example questions & explanations for Intermediate Geometry

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Example Questions

Example Question #6 : How To Find The Length Of A Line With Distance Formula

Find the distance of the line connecting the pair of points

 and .

Possible Answers:

Correct answer:

Explanation:

By the distance formula 

where  and 

we have

Example Question #7 : How To Find The Length Of A Line With Distance Formula

Find the length of for

Possible Answers:

Correct answer:

Explanation:

To find the distance, first we have to find the specific coordinate pairs that we're finding the distance between. We know the x-values, so to find the y-values we can plug these endpoint x-values into the line:

first multiply

then subtract

 

first multiply 

then subtract

Now we know that we're finding the distance between the points and . We can just plug these values into the distance formula, using the first pair as and the second pair as . It would work either way since we are squaring these values, this just makes it easier.

Example Question #8 : How To Find The Length Of A Line With Distance Formula

Find the length of for

Possible Answers:

Correct answer:

Explanation:

To find the distance, first we have to find the specific coordinate pairs that we're finding the distance between. We know the x-values, so to find the y-values we can plug these endpoint x-values into the line:

 first multiply

 then add

 

 first multiply 

 then add

Now we know that we're finding the distance between the points  and . We can just plug these values into the distance formula, using the first pair as and the second pair as . Note that it would work either way since we are squaring these values anyway.

Example Question #9 : How To Find The Length Of A Line With Distance Formula

Find the length of the line for

Possible Answers:

Correct answer:

Explanation:

To find the distance, first we have to find the specific coordinate pairs that we're finding the distance between. We know the y-values, so to find the x-values we can plug these endpoint y-values into the line:

add 6 to both sides

multiply by 2

this endpoint is (10, -1)

 

add 6 to both sides

multiply by 2

this endpoint is (28, 8)

 

Now we can plug these two endpoints into the distance formula:

note that it really does not matter which pair we use as and which as since we'll be squaring these differences anyway, just as long as we are consistent.

Example Question #1 : How To Find The Length Of A Line With Distance Formula

Find the length of for the interval .

Possible Answers:

Correct answer:

Explanation:

To find this length, we need to know the y-coordinates for the endpoints.

First, plug in -5 for x:

Next, plug in 10 for x:

So we are finding the distance between the points and

We will use the distance formula, . We could assign either point as and it would still work, but let's choose :

Example Question #11 : Distance Formula

Find the length of for the interval .

Possible Answers:

Correct answer:

Explanation:

First, we need to figure out the x-coordinates of the endpoints so that we can use the distance formula,

Plug in -10 for y and solve for x:

subtract 3 from both sides

divide both sides by -2

Plug in 15 for y and solve for x:

subtract 3 from both sides

divide both sides by -2 

The endpoints are and . We could choose either point to be . Let's choose .

Example Question #12 : Distance Formula

Find the length of the line for the interval .

Possible Answers:

Correct answer:

Explanation:

To calculate the distance, first find the y-coordinates of the endpoints by plugging the x-coordinates into the equation.

First plug in -5

  combining like terms, we get -10 + 10 is 0 

divide by -4

Now plug in 0

subtract 10 from both sides

divide by -4

The endpoints are and , and now we can plug these points into the distance formula:

Example Question #13 : Distance Formula

Find the length of on the interval .

Possible Answers:

Correct answer:

Explanation:

To find the length, we need to first find the y-coordinates of the endpoints.

First, plug in -8 for x:

Now plug in 12 for x:

Our endpoints are and .

To find the length, plug these points into the distance formula:

Example Question #14 : Distance Formula

Jose is walking from his house to the grocery store. He walks 120 feet north, then turns left to walk another 50 feet west. On the way back home, Jose finds a straight line shortcut back to his house. How long is this shortcut? 

Possible Answers:

Correct answer:

Explanation:

When walking north and then taking a left west, a 90 degree angle is formed. When Jose returns home going in a straight line, this will now form the hypotenuse of a right triangle. The legs of the triangle are 120 ft and 50 ft respectively. 

To solve, use the pythagorean formula. 

130 ft is the straight line distance home. 

The distance formula could also be used to solve this problem. 

We will assume that home is at the point (0,0)

Distance = 130 ft. 

 

Example Question #11 : How To Find The Length Of A Line With Distance Formula

A line has endpoints at (8,4) and (5,10). How long is this line?

Possible Answers:

7

None of these.

Correct answer:

Explanation:

We find the exact length of lines using their endpoints and the distance formula.

Given the endpoints,

the distance formula becomes,

.

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