Question

A right triangle has sides measuring 5 inches, 12 inches, and 13 inches. What is the area, in square inches, of this triangle ?

Answer 1

Please look up and apply Heron's Formula.  Start by calculating s, where
        a  +  b  +  c
s = -------------------
               2

Then calculate A:

A = sqrt[ s(s-a)(s-b)(s-c) ]