The base of a triangle is 3 cm and the height is 5 cm. what mathematical operation(s) described must be performed in order to find the area of this triangle?
a) multiply 3 and 5
b) add 3 and 5, then divide the sum by 2
c) multiply 3 and 5, then divide the product by 2
d) use the pythagorean theorem to find the missing sides of the triangle and then add the three sides together