# GMAT Math : Calculating the perimeter of an equilateral triangle

## Example Questions

### Example Question #17 : Equilateral Triangles

The area of an equilateral triangle  is . What is the perimeter of ?

Explanation:

The area is given, which will allow us to calculate the side of the triangle and hence we can also find the perimeter.

The area for an equilateral triangle is given by the formula

, where  is the length of the side of the triangle.

Therefore, , where  is the area.

Thus , and the perimeter of an equilateral triangle is three times the side, hence, the final answer is .

### Example Question #18 : Equilateral Triangles

A given equilateral triangle has a side length of . What is the perimeter of the triangle?

Not enough information provided.

Explanation:

An equilateral triangle with a side length  has a perimeter .

Given:

### Example Question #19 : Equilateral Triangles

A given equilateral triangle has a side length of . What is the perimeter of the triangle?

Explanation:

An equilateral triangle with a side length  has a perimeter .

Given:

### Example Question #20 : Equilateral Triangles

A given equilateral triangle has a side length of . What is the perimeter of the triangle?

Not enough information provided.

Explanation:

An equilateral triangle with a side length  has a perimeter .

Given:

### Example Question #21 : Equilateral Triangles

Given the following regarding Triangle .

I)

II) Side  is equal to  light-years

What is the length of side ?

light years

light years

light years

light years

light years

light years

Explanation:

The trick to this one is to carefully put together what you are given.

We know that two of our angles are equal to 60 degrees. This means that the last angle is also 60 degrees. This make HFT an equilateral triangle.

Equilateral triangles always have equal sides and equal angles, so our last side has to be 7 light years as well.

### Example Question #22 : Equilateral Triangles

Calculate the perimeter of an equilateral triangle whose side length is .

Explanation:

The perimeter of an equilateral triangle is:

Thus.

### Example Question #23 : Equilateral Triangles

Find the perimeter of an equilateral triangle whose side length is .

Explanation:

To find the perimeter, you must multiply the side length by . Thus,

### Example Question #24 : Equilateral Triangles

Calculate the perimeter of an equilateral triangle whose side length is .