Find the area of an equilateral triangle (regular 3-gon) with the given measurement. 6-inch side. A = sq. in.

Using Heron's formula where s = 9 ...... and a = b = c = the side lengths .....we have......

A = √[s(s -a)^3] =  √[9*3^3]   = √[9*27] = √[9*9*3] =   √[81*3)   = 9√3  sq. in.