Question

An equilateral triangle has a perimeter of 60m and a height of 17.3m. what is its area?

Answer 1

Divide 60/3 so you get 20. So take 20x17.3 and you should get 346m∧2

Answer 2

The area of any triangle is            (1/2) x (length of the base) x (height) .

In this problem, we know the triangle's height,
but what is the length of the base ?

The base is the side that the triangle is sitting on.  This particular triangle
is an equilateral one, and its perimeter is 60m.  So each side must be 20m. 
No matter which side the triangle is sitting on, the length of the base is 20m.

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

           Area = (1/2) x (20m) x (17.3m) =  173 m²