Area of a Triangle (P.77 Ex.9)
Write a program to calculate the area of a triangle given the length of
its three sides a, b, and c using these formulas:
- s = (a + b + c) / 2
- A = sqrt( s(s-a)(s-b)(s-c) )
The program may run as follows:
2.0, 2.0, 2.0
1.7320508075688772