Intermediate Geometry : How to find the area of an equilateral triangle

Study concepts, example questions & explanations for Intermediate Geometry

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Example Questions

Example Question #51 : Equilateral Triangles

A circle is placed in an equilateral triangle as shown by the figure.

8

If the radius of the circle is , find the area of the shaded region.

Possible Answers:

Correct answer:

Explanation:

13

In order to find the area of the shaded region, you must first find the areas of the triangle and circle.

First, recall how to find the area of an equilateral triangle:

Substitute in the value of the side to find the area of the triangle.

Next, recall how to find the area of a circle.

Substitute in the value of the radius to find the area of the circle.

Finally, find the area of the shaded region.

Solve and round to two decimal places.

Example Question #52 : Equilateral Triangles

A circle is placed in an equilateral triangle as shown by the figure.

9

If the radius of the circle is , find the area of the shaded region.

Possible Answers:

Correct answer:

Explanation:

13

In order to find the area of the shaded region, you must first find the areas of the triangle and circle.

First, recall how to find the area of an equilateral triangle:

Substitute in the value of the side to find the area of the triangle.

Next, recall how to find the area of a circle.

Substitute in the value of the radius to find the area of the circle.

Finally, find the area of the shaded region.

Solve and round to two decimal places.

Example Question #53 : Equilateral Triangles

A circle is placed in an equilateral triangle as shown by the figure.

10

If the radius of the circle is , find the area of the shaded region.

Possible Answers:

Correct answer:

Explanation:

13

In order to find the area of the shaded region, you must first find the areas of the triangle and circle.

First, recall how to find the area of an equilateral triangle:

Substitute in the value of the side to find the area of the triangle.

Next, recall how to find the area of a circle.

Substitute in the value of the radius to find the area of the circle.

Finally, find the area of the shaded region.

Solve and round to two decimal places.

Example Question #54 : Equilateral Triangles

A circle is placed in an equilateral triangle as shown by the figure.

11

If the radius of the circle is , find the area of the shaded region.

Possible Answers:

Correct answer:

Explanation:

13

In order to find the area of the shaded region, you must first find the areas of the triangle and circle.

First, recall how to find the area of an equilateral triangle:

Substitute in the value of the side to find the area of the triangle.

Next, recall how to find the area of a circle.

Substitute in the value of the radius to find the area of the circle.

Finally, find the area of the shaded region.

Solve and round to two decimal places.

Example Question #55 : Equilateral Triangles

A circle is placed in an equilateral triangle as shown by the figure.

12

If the radius of the circle is , find the area of the shaded region.

Possible Answers:

Correct answer:

Explanation:

13

In order to find the area of the shaded region, you must first find the areas of the triangle and circle.

First, recall how to find the area of an equilateral triangle:

Substitute in the value of the side to find the area of the triangle.

Next, recall how to find the area of a circle.

Substitute in the value of the radius to find the area of the circle.

Finally, find the area of the shaded region.

Solve and round to two decimal places.

Example Question #56 : Equilateral Triangles

An equilateral triangle is placed on top of a regular hexagon as shown by the figure below.

1

Find the area of the entire figure.

Possible Answers:

Correct answer:

Explanation:

13

Recall that a regular hexagon can be divided into  congruent equilateral triangles.

Since the extra equilateral triangle on top has the same side lengths as of the equilateral triangles made by dividing the hexagon, the entire figure has a total of  congruent equilateral triangles.

Thus, to find the area of the entire figure, we must first find the area of the equilateral triangle.

Recall how to find the area of an equilateral triangle:

Plug in the length of a side of the equilateral triangle.

Now, multiply this area by  to find the area of the entire figure.

Make sure to round to  places after the decimal.

Example Question #57 : Equilateral Triangles

An equilateral triangle is placed on top of a regular hexagon as shown by the figure below.

2

Find the area of the entire figure.

Possible Answers:

The area of the entire figure cannot be determined by the given information.

Correct answer:

Explanation:

13

Recall that a regular hexagon can be divided into  congruent equilateral triangles.

Since the extra equilateral triangle on top has the same side lengths as of the equilateral triangles made by dividing the hexagon, the entire figure has a total of  congruent equilateral triangles.

Thus, to find the area of the entire figure, we must first find the area of the equilateral triangle.

Recall how to find the area of an equilateral triangle:

Plug in the length of a side of the equilateral triangle.

Now, multiply this area by  to find the area of the entire figure.

Make sure to round to  places after the decimal.

Example Question #58 : Equilateral Triangles

An equilateral triangle is placed on top of a regular hexagon as shown by the figure below.

3

Find the area of the entire figure.

Possible Answers:

Correct answer:

Explanation:

13

Recall that a regular hexagon can be divided into  congruent equilateral triangles.

Since the extra equilateral triangle on top has the same side lengths as of the equilateral triangles made by dividing the hexagon, the entire figure has a total of  congruent equilateral triangles.

Thus, to find the area of the entire figure, we must first find the area of the equilateral triangle.

Recall how to find the area of an equilateral triangle:

Plug in the length of a side of the equilateral triangle.

Now, multiply this area by  to find the area of the entire figure.

Make sure to round to  places after the decimal.

Example Question #31 : How To Find The Area Of An Equilateral Triangle

An equilateral triangle is placed on top of a regular hexagon as shown by the figure below.

4

Possible Answers:

Correct answer:

Explanation:

13

Recall that a regular hexagon can be divided into  congruent equilateral triangles.

Since the extra equilateral triangle on top has the same side lengths as of the equilateral triangles made by dividing the hexagon, the entire figure has a total of  congruent equilateral triangles.

Thus, to find the area of the entire figure, we must first find the area of the equilateral triangle.

Recall how to find the area of an equilateral triangle:

Plug in the length of a side of the equilateral triangle.

Now, multiply this area by  to find the area of the entire figure.

Make sure to round to  places after the decimal.

Example Question #32 : How To Find The Area Of An Equilateral Triangle

An equilateral triangle is placed on top of a regular hexagon as shown by the figure below.

5

Find the area of the entire figure.

Possible Answers:

Correct answer:

Explanation:

13

Recall that a regular hexagon can be divided into  congruent equilateral triangles.

Since the extra equilateral triangle on top has the same side lengths as of the equilateral triangles made by dividing the hexagon, the entire figure has a total of  congruent equilateral triangles.

Thus, to find the area of the entire figure, we must first find the area of the equilateral triangle.

Recall how to find the area of an equilateral triangle:

Plug in the length of a side of the equilateral triangle.

Now, multiply this area by  to find the area of the entire figure.

Make sure to round to  places after the decimal.

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