Basic Geometry : How to find the perimeter of a square

Study concepts, example questions & explanations for Basic Geometry

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Example Questions

Example Question #471 : Quadrilaterals

Find the perimeter of a square inscribed in a circle that has a diameter of \(\displaystyle 9\sqrt2\).

Possible Answers:

\(\displaystyle 36\sqrt2\)

\(\displaystyle 72\)

\(\displaystyle 18\sqrt2\)

\(\displaystyle 36\)

Correct answer:

\(\displaystyle 36\)

Explanation:

1

Notice that the diameter of the circle is also the diagonal of the square. The diagonal of the square is also the hypotenuse of a right isosceles triangle that has the sides of the square as its legs.

\(\displaystyle \text{diameter}=\text{diagonal}\)

Now, use the Pythagorean theorem to find the length of the sides of the square.

\(\displaystyle \text{Diagonal}^2=\text{side}^2+\text{side}^2\)

\(\displaystyle 2(\text{side})^2=\text{Diagonal}^2\)

\(\displaystyle \text{side}^2=\frac{\text{Diagonal}^2}{2}\) 

\(\displaystyle \text{side}=\sqrt{\frac{\text{Diagonal}^2}{2}}=\frac{\text{Diagonal}\sqrt2}{2}\)

Now, substitute in the value of the diagonal to find the length of a side of the square.

\(\displaystyle \text{side}=\frac{9\sqrt2(\sqrt2)}{2}\)

Simplify.

\(\displaystyle \text{side}=9\)

Now, recall how to find the perimeter of a square:

\(\displaystyle \text{Perimeter}=4(\text{side})\)

Substitute in the value of the side to find the perimeter of the square.

\(\displaystyle \text{Perimeter}=4(9)\)

Solve.

\(\displaystyle \text{Perimeter}=36\)

Example Question #472 : Quadrilaterals

Find the perimeter of a square inscribed in a circle that has a diameter of \(\displaystyle 11\sqrt2\).

Possible Answers:

\(\displaystyle 121\sqrt2\)

\(\displaystyle 22\sqrt2\)

\(\displaystyle 44\)

\(\displaystyle 22\)

Correct answer:

\(\displaystyle 44\)

Explanation:

1

Notice that the diameter of the circle is also the diagonal of the square. The diagonal of the square is also the hypotenuse of a right isosceles triangle that has the sides of the square as its legs.

\(\displaystyle \text{diameter}=\text{diagonal}\)

Now, use the Pythagorean theorem to find the length of the sides of the square.

\(\displaystyle \text{Diagonal}^2=\text{side}^2+\text{side}^2\)

\(\displaystyle 2(\text{side})^2=\text{Diagonal}^2\)

\(\displaystyle \text{side}^2=\frac{\text{Diagonal}^2}{2}\) 

\(\displaystyle \text{side}=\sqrt{\frac{\text{Diagonal}^2}{2}}=\frac{\text{Diagonal}\sqrt2}{2}\)

Now, substitute in the value of the diagonal to find the length of a side of the square.

\(\displaystyle \text{side}=\frac{11\sqrt2(\sqrt2)}{2}\)

Simplify.

\(\displaystyle \text{side}=11\)

Now, recall how to find the perimeter of a square:

\(\displaystyle \text{Perimeter}=4(\text{side})\)

Substitute in the value of the side to find the perimeter of the square.

\(\displaystyle \text{Perimeter}=4(11)\)

Solve.

\(\displaystyle \text{Perimeter}=44\)

Example Question #480 : Quadrilaterals

Find the perimeter of a square inscribed in a circle that has a diameter of \(\displaystyle 13\sqrt2\).

Possible Answers:

\(\displaystyle 52\sqrt3\)

\(\displaystyle 52\)

\(\displaystyle 52\sqrt2\)

\(\displaystyle 104\)

Correct answer:

\(\displaystyle 52\)

Explanation:

1

Notice that the diameter of the circle is also the diagonal of the square. The diagonal of the square is also the hypotenuse of a right isosceles triangle that has the sides of the square as its legs.

\(\displaystyle \text{diameter}=\text{diagonal}\)

Now, use the Pythagorean theorem to find the length of the sides of the square.

\(\displaystyle \text{Diagonal}^2=\text{side}^2+\text{side}^2\)

\(\displaystyle 2(\text{side})^2=\text{Diagonal}^2\)

\(\displaystyle \text{side}^2=\frac{\text{Diagonal}^2}{2}\) 

\(\displaystyle \text{side}=\sqrt{\frac{\text{Diagonal}^2}{2}}=\frac{\text{Diagonal}\sqrt2}{2}\)

Now, substitute in the value of the diagonal to find the length of a side of the square.

\(\displaystyle \text{side}=\frac{13\sqrt2(\sqrt2)}{2}\)

Simplify.

\(\displaystyle \text{side}=13\)

Now, recall how to find the perimeter of a square:

\(\displaystyle \text{Perimeter}=4(\text{side})\)

Substitute in the value of the side to find the perimeter of the square.

\(\displaystyle \text{Perimeter}=4(13)\)

Solve.

\(\displaystyle \text{Perimeter}=52\)

Example Question #481 : Quadrilaterals

Find the perimeter of a square inscribed in a circle that has a diameter of \(\displaystyle 15\sqrt2\).

Possible Answers:

\(\displaystyle 120\)

\(\displaystyle 90\)

\(\displaystyle 60\)

\(\displaystyle 180\)

Correct answer:

\(\displaystyle 60\)

Explanation:

1

Notice that the diameter of the circle is also the diagonal of the square. The diagonal of the square is also the hypotenuse of a right isosceles triangle that has the sides of the square as its legs.

\(\displaystyle \text{diameter}=\text{diagonal}\)

Now, use the Pythagorean theorem to find the length of the sides of the square.

\(\displaystyle \text{Diagonal}^2=\text{side}^2+\text{side}^2\)

\(\displaystyle 2(\text{side})^2=\text{Diagonal}^2\)

\(\displaystyle \text{side}^2=\frac{\text{Diagonal}^2}{2}\) 

\(\displaystyle \text{side}=\sqrt{\frac{\text{Diagonal}^2}{2}}=\frac{\text{Diagonal}\sqrt2}{2}\)

Now, substitute in the value of the diagonal to find the length of a side of the square.

\(\displaystyle \text{side}=\frac{15\sqrt2(\sqrt2)}{2}\)

Simplify.

\(\displaystyle \text{side}=15\)

Now, recall how to find the perimeter of a square:

\(\displaystyle \text{Perimeter}=4(\text{side})\)

Substitute in the value of the side to find the perimeter of the square.

\(\displaystyle \text{Perimeter}=4(15)\)

Solve.

\(\displaystyle \text{Perimeter}=60\)

Example Question #482 : Quadrilaterals

Find the perimeter of a square inscribed in a circle that has a diameter of \(\displaystyle 12\sqrt2\).

Possible Answers:

\(\displaystyle 60\)

\(\displaystyle 36\)

\(\displaystyle 48\)

\(\displaystyle 24\)

Correct answer:

\(\displaystyle 48\)

Explanation:

1

Notice that the diameter of the circle is also the diagonal of the square. The diagonal of the square is also the hypotenuse of a right isosceles triangle that has the sides of the square as its legs.

\(\displaystyle \text{diameter}=\text{diagonal}\)

Now, use the Pythagorean theorem to find the length of the sides of the square.

\(\displaystyle \text{Diagonal}^2=\text{side}^2+\text{side}^2\)

\(\displaystyle 2(\text{side})^2=\text{Diagonal}^2\)

\(\displaystyle \text{side}^2=\frac{\text{Diagonal}^2}{2}\) 

\(\displaystyle \text{side}=\sqrt{\frac{\text{Diagonal}^2}{2}}=\frac{\text{Diagonal}\sqrt2}{2}\)

Now, substitute in the value of the diagonal to find the length of a side of the square.

\(\displaystyle \text{side}=\frac{12\sqrt2(\sqrt2)}{2}\)

Simplify.

\(\displaystyle \text{side}=12\)

Now, recall how to find the perimeter of a square:

\(\displaystyle \text{Perimeter}=4(\text{side})\)

Substitute in the value of the side to find the perimeter of the square.

\(\displaystyle \text{Perimeter}=4(12)\)

Solve.

\(\displaystyle \text{Perimeter}=48\)

Example Question #483 : Quadrilaterals

Find the perimeter of a square inscribed in a circle that has a diameter of \(\displaystyle 19\sqrt2\).

Possible Answers:

\(\displaystyle 90\)

\(\displaystyle 76\sqrt2\)

\(\displaystyle 76\)

\(\displaystyle 104\)

Correct answer:

\(\displaystyle 76\)

Explanation:

1

Notice that the diameter of the circle is also the diagonal of the square. The diagonal of the square is also the hypotenuse of a right isosceles triangle that has the sides of the square as its legs.

\(\displaystyle \text{diameter}=\text{diagonal}\)

Now, use the Pythagorean theorem to find the length of the sides of the square.

\(\displaystyle \text{Diagonal}^2=\text{side}^2+\text{side}^2\)

\(\displaystyle 2(\text{side})^2=\text{Diagonal}^2\)

\(\displaystyle \text{side}^2=\frac{\text{Diagonal}^2}{2}\) 

\(\displaystyle \text{side}=\sqrt{\frac{\text{Diagonal}^2}{2}}=\frac{\text{Diagonal}\sqrt2}{2}\)

Now, substitute in the value of the diagonal to find the length of a side of the square.

\(\displaystyle \text{side}=\frac{19\sqrt2(\sqrt2)}{2}\)

Simplify.

\(\displaystyle \text{side}=19\)

Now, recall how to find the perimeter of a square:

\(\displaystyle \text{Perimeter}=4(\text{side})\)

Substitute in the value of the side to find the perimeter of the square.

\(\displaystyle \text{Perimeter}=4(19)\)

Solve.

\(\displaystyle \text{Perimeter}=76\)

Example Question #484 : Quadrilaterals

Find the perimeter of a square inscribed in a circle that has a diameter of \(\displaystyle 20\).

Possible Answers:

\(\displaystyle 40\sqrt2\)

\(\displaystyle 120\)

\(\displaystyle 80\)

\(\displaystyle 160\sqrt2\)

Correct answer:

\(\displaystyle 40\sqrt2\)

Explanation:

1

Notice that the diameter of the circle is also the diagonal of the square. The diagonal of the square is also the hypotenuse of a right isosceles triangle that has the sides of the square as its legs.

\(\displaystyle \text{diameter}=\text{diagonal}\)

Now, use the Pythagorean theorem to find the length of the sides of the square.

\(\displaystyle \text{Diagonal}^2=\text{side}^2+\text{side}^2\)

\(\displaystyle 2(\text{side})^2=\text{Diagonal}^2\)

\(\displaystyle \text{side}^2=\frac{\text{Diagonal}^2}{2}\) 

\(\displaystyle \text{side}=\sqrt{\frac{\text{Diagonal}^2}{2}}=\frac{\text{Diagonal}\sqrt2}{2}\)

Now, substitute in the value of the diagonal to find the length of a side of the square.

\(\displaystyle \text{side}=\frac{20(\sqrt2)}{2}\)

Simplify.

\(\displaystyle \text{side}=10\sqrt2\)

Now, recall how to find the perimeter of a square:

\(\displaystyle \text{Perimeter}=4(\text{side})\)

Substitute in the value of the side to find the perimeter of the square.

\(\displaystyle \text{Perimeter}=4(10\sqrt2)\)

Solve.

\(\displaystyle \text{Perimeter}=40\sqrt2\)

Example Question #485 : Quadrilaterals

Find the perimeter of a square inscribed in a circle that has a diameter of \(\displaystyle 12\).

Possible Answers:

\(\displaystyle 144\)

\(\displaystyle 36\sqrt2\)

\(\displaystyle 24\sqrt2\)

\(\displaystyle 48\sqrt2\)

Correct answer:

\(\displaystyle 24\sqrt2\)

Explanation:

1

Notice that the diameter of the circle is also the diagonal of the square. The diagonal of the square is also the hypotenuse of a right isosceles triangle that has the sides of the square as its legs.

\(\displaystyle \text{diameter}=\text{diagonal}\)

Now, use the Pythagorean theorem to find the length of the sides of the square.

\(\displaystyle \text{Diagonal}^2=\text{side}^2+\text{side}^2\)

\(\displaystyle 2(\text{side})^2=\text{Diagonal}^2\)

\(\displaystyle \text{side}^2=\frac{\text{Diagonal}^2}{2}\) 

\(\displaystyle \text{side}=\sqrt{\frac{\text{Diagonal}^2}{2}}=\frac{\text{Diagonal}\sqrt2}{2}\)

Now, substitute in the value of the diagonal to find the length of a side of the square.

\(\displaystyle \text{side}=\frac{12(\sqrt2)}{2}\)

Simplify.

\(\displaystyle \text{side}=6\sqrt2\)

Now, recall how to find the perimeter of a square:

\(\displaystyle \text{Perimeter}=4(\text{side})\)

Substitute in the value of the side to find the perimeter of the square.

\(\displaystyle \text{Perimeter}=4(6\sqrt2)\)

Solve.

\(\displaystyle \text{Perimeter}=24\sqrt2\)

Example Question #486 : Quadrilaterals

Find the perimeter of a square inscribed in a circle that has a diameter of \(\displaystyle 14\).

Possible Answers:

\(\displaystyle 28\sqrt2\)

\(\displaystyle 35\sqrt2\)

\(\displaystyle 14\sqrt2\)

\(\displaystyle 42\sqrt2\)

Correct answer:

\(\displaystyle 28\sqrt2\)

Explanation:

1

Notice that the diameter of the circle is also the diagonal of the square. The diagonal of the square is also the hypotenuse of a right isosceles triangle that has the sides of the square as its legs.

\(\displaystyle \text{diameter}=\text{diagonal}\)

Now, use the Pythagorean theorem to find the length of the sides of the square.

\(\displaystyle \text{Diagonal}^2=\text{side}^2+\text{side}^2\)

\(\displaystyle 2(\text{side})^2=\text{Diagonal}^2\)

\(\displaystyle \text{side}^2=\frac{\text{Diagonal}^2}{2}\) 

\(\displaystyle \text{side}=\sqrt{\frac{\text{Diagonal}^2}{2}}=\frac{\text{Diagonal}\sqrt2}{2}\)

Now, substitute in the value of the diagonal to find the length of a side of the square.

\(\displaystyle \text{side}=\frac{14(\sqrt2)}{2}\)

Simplify.

\(\displaystyle \text{side}=7\sqrt2\)

Now, recall how to find the perimeter of a square:

\(\displaystyle \text{Perimeter}=4(\text{side})\)

Substitute in the value of the side to find the perimeter of the square.

\(\displaystyle \text{Perimeter}=4(7\sqrt2)\)

Solve.

\(\displaystyle \text{Perimeter}=28\sqrt2\)

Example Question #487 : Quadrilaterals

Find the perimeter of a square inscribed in a circle that has a diameter of \(\displaystyle 16\).

Possible Answers:

\(\displaystyle 24\sqrt2\)

\(\displaystyle 32\sqrt2\)

\(\displaystyle 64\)

\(\displaystyle 16\sqrt2\)

Correct answer:

\(\displaystyle 32\sqrt2\)

Explanation:

1

Notice that the diameter of the circle is also the diagonal of the square. The diagonal of the square is also the hypotenuse of a right isosceles triangle that has the sides of the square as its legs.

\(\displaystyle \text{diameter}=\text{diagonal}\)

Now, use the Pythagorean theorem to find the length of the sides of the square.

\(\displaystyle \text{Diagonal}^2=\text{side}^2+\text{side}^2\)

\(\displaystyle 2(\text{side})^2=\text{Diagonal}^2\)

\(\displaystyle \text{side}^2=\frac{\text{Diagonal}^2}{2}\) 

\(\displaystyle \text{side}=\sqrt{\frac{\text{Diagonal}^2}{2}}=\frac{\text{Diagonal}\sqrt2}{2}\)

Now, substitute in the value of the diagonal to find the length of a side of the square.

\(\displaystyle \text{side}=\frac{16(\sqrt2)}{2}\)

Simplify.

\(\displaystyle \text{side}=8\sqrt2\)

Now, recall how to find the perimeter of a square:

\(\displaystyle \text{Perimeter}=4(\text{side})\)

Substitute in the value of the side to find the perimeter of the square.

\(\displaystyle \text{Perimeter}=4(8\sqrt2)\)

Solve.

\(\displaystyle \text{Perimeter}=32\sqrt2\)

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