What is the Surface area of isosceles triangle?

Ok to find the area of an isosceles triangle:

Find the height first, to do this use this formula:

Height = Square root ( one side square - half the base square)

Now that you have the height you can calculate the area by the use of this formula:

Area = (1/2)(base)(height)

This will give you the surface area of an isosceles triangle.

Lets do an example:

You have a triangle that has two sides that measure 24 meters and a base of 20 meters.

Using the formula above for height you will get a height of 21.8 meters

Now use the formula above to find the area and it will give you an area of 218 meters square