# GRE Math : How to find the length of the side of an equilateral triangle

## Example Questions

### Example Question #1 : Equilateral Triangles

What is the length of a side of an equilateral triangle if the area is ?      Explanation:

The area of an equilateral triangle is .

So let's set-up an equation to solve for  Cross multiply. The cancels out and we get .

Then take square root on both sides and we get as the final answer.

### Example Question #2 : Equilateral Triangles

If the height of the equilateral triangle is , then what is the length of a side of an equilateral triangle?      Explanation:

By having a height in an equilateral triangle, the angle is bisected therefore creating two triangles.

The height is opposite the angle . We can set-up a proportion.

Side opposite is and the side of equilateral triangle which is opposite is . Cross multiply. Divide both sides by  Multiply top and bottom by to get rid of the radical. Tired of practice problems?

Try live online GRE Math prep today. 