8. Answer:
Imagine opening the Triangular prism
We will have 2 triangles at the base
and 3 rectangles
The sides of the triangle : base 9in, height 3in
Area of Triangle
=

Now the rectangles
Rectangle1 with sides 9in and 15in, Area = 9*15 = 135
Rectangle 2 with sides 5in and 15in , Area = 5*15 = 75
Rectangle 3 with sides 6in and 15in, Area = 6*15 = 90
Now the total area of the prism
=
