Answer:
4
Step-by-step explanation:
What you have typed is

=3^12 cancels out

=4
The answer is 3 because 3.75 divided by 2.5 is 1.5 , and when finding the area of a triangle you have to cut one of the sides values in half then multiply it by the other side. So 2.5 times 3 equals 7.5 and then divided by 2 is 3.75.
That would be net A
Surface area = 13*16 + 12 * 16 + 2 (1/2*5*12) + 5*16
= 540 in^2