posted by Punkie on .
I am to find the area of an equilateral triangle whose side is 5... I know I need to find the highth before I find the area, but I end up with a hight of the square root of 31.25, is this right? if so how do I continue and solve for the area with this kind of number?
Area = 1/2 Base * height
With Pythagorean theorem for half of the triangle to give you the height:
5^2 = 2.5^2 + h^2
25 = 6.25 + h^2
h^2 = 25 - 6.25 = 18.75
Find square root of 18.75 and insert values into the first equation.
I hope this helps.