The perimeter of a triangle is 42 cm and the inradius of the triangle is 5.0 cm. What is the area of the triangle? Select.
A) 128 cm 2	B) 36.0 cm 2	C) 105 cm 2	D) 25 cm 2	E) 135 cm 2

Rationale: "area of a triangle = r * s where r is the inradius and s is the semi perimeter of the triangle . area of triangle = 5.0 * 42 / 2 = 105 cm 2 answer : c"
Answer: C