There are several ways to find the area of a polygon, but because you're in middle school, you'll most likely use; A = 1/2b * h; where A = area, b = base, and h= height.
Say you have a triangle, the bottom of it is 4 meters and it is 6 meters tall this is not the same thing as a side length. You would divide 4 by 2, which is the same thing as as multiplying by 1/2, and multiply it by 6.
So A = 1/2*2*6
A = 1 * 6
A = 6
