If the three lengths of the sides of a triangle are known, Heron's formula can be used to find its area. If a, b, and c are the three lengths of the sides, Heron's formula for area is:
A =
where s is half the perimeter of the triangle, or s =
(a + b + c).
Use this formula to approximate the area of the triangle to two decimal places, if necessary, when a = 9 cm, b = 11 cm and c = 16 cm.
◦ 9.76 sq cm
◦ 47.62 sq cm
◦ 11.22 sq cm
◦ 697.14 sq cm