Find the area of an equilateral triangle (regular 3-gon) with the given measurement.
4-inch side
A = sq. in.
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Using Heron's formula where s = 9 ...... and a = b = c = the side lengths .....we have......
A = √[s(s -a)^3] = √[4*3^3] = √[4*27] = √[4*9*3] = √[36*3) = 9√3 sq. in.