Intermediate Geometry : How to find the length of the side of a pentagon

Study concepts, example questions & explanations for Intermediate Geometry

varsity tutors app store varsity tutors android store

Example Questions

Example Question #778 : Intermediate Geometry

If the area of a regular pentagon is , and the length of the apothem is , what is the length of a side of the pentagon?

Possible Answers:

Correct answer:

Explanation:

Recall how to find the area of a regular pentagon:

Now, the perimeter of a regular pentagon can be found by multiplying the side length by :

Substitute this into the equation for the area.

Now, rearrange the equation to solve for the side length.

Plug in the given area and apothem to solve for the side length of the pentagon.

Make sure to round to two places after the decimal.

Example Question #779 : Intermediate Geometry

If the area of a regular pentagon is , and the length of the apothem is , what is the length of a side of the pentagon?

Possible Answers:

Correct answer:

Explanation:

Recall how to find the area of a regular pentagon:

Now, the perimeter of a regular pentagon can be found by multiplying the side length by :

Substitute this into the equation for the area.

Now, rearrange the equation to solve for the side length.

Plug in the given area and apothem to solve for the side length of the pentagon.

Make sure to round to two places after the decimal.

Example Question #780 : Intermediate Geometry

If the area of a regular pentagon is , and the length of the apothem is , what is the length of the side of the pentagon?

Possible Answers:

Correct answer:

Explanation:

Recall how to find the area of a regular pentagon:

Now, the perimeter of a regular pentagon can be found by multiplying the side length by :

Substitute this into the equation for the area.

Now, rearrange the equation to solve for the side length.

Plug in the given area and apothem to solve for the side length of the pentagon.

Make sure to round to two places after the decimal.

Example Question #41 : Pentagons

If the area of a regular pentagon is , and the length of the apothem is , what is the length of a side of the pentagon?

Possible Answers:

Correct answer:

Explanation:

Recall how to find the area of a regular pentagon:

Now, the perimeter of a regular pentagon can be found by multiplying the side length by :

Substitute this into the equation for the area.

Now, rearrange the equation to solve for the side length.

Plug in the given area and apothem to solve for the side length of the pentagon.

Make sure to round to two places after the decimal.

Example Question #43 : Pentagons

In pentagon , if the length of  is one-fifth the length of , what is the length of the side ?

3

Possible Answers:

Correct answer:

Explanation:

3

Notice that this pentagon is made up of one rectangle and two right triangles. In order to find the length of , we will first need to find the length of .

Let  be the length of , so then the length of  can be represented by .

Since we have rectangle , we know that .

Thus, 

Now, plug in the variables and solve for .

Thus, we know that .

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

Make sure to round to  places after the decimal.

Learning Tools by Varsity Tutors