Medium
Using Heron's formula, find the area of a triangle with sides 7 cm, 8 cm, and 9 cm.
Explanation
Explanation
Semi-perimeter s = (7+8+9)/2 = 12.0. By Heron's formula, Area = √[s(s-a)(s-b)(s-c)] = √[12.0 × 5.0 × 4.0 × 3.0] = √720.00 ≈ 26.83 cm².
PRO TIP
Re-check your working by substituting the answer back into the original question.