Task: Question Answering
Input (English): Problem: 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 ?
Options: a. 128 cm 2, b. 36.0 cm 2, c. 105 cm 2, d. 25 cm 2, e. 135 cm 2
Output (English): c