Answer:
D
Explanation:
You need to find the volume of the attic (I would find the surface area myself -- but this is math. You just have to obey the rules of the question no matter how silly).
The Volume is found by V = B * h1
The base is a triangle.
b = 7 m
h1 = 10 m
Area = 1/2 * 7 * 10
area = 35 m^2
The volume of the attic is
V = B * h
V = 35 * 13
V = 455 m^3
The cost = cost /m^3 * m^3
m^3 = 455
Cost = 3.15 * 455
Cost = 1433.25