2 Geometry problems...?

Question

Find the surface area and volume of a right rectangular prism with the given dimensions.
5) L=4, W=12, H=15
6) L=21, W=21, H=21


Thanks to anyone who can help :)

Answer 1

5) volume is 4*12*15 and the surface area is 2*(4*12)+2*(4*15)+2*(12*15)
6) same process

Answer 2

Basicall you find the area of every side. This particular prism has 6 sides.

2 sides with the dimensions 4x12
2 w/ 4 x 15
and 2 w/ 12 x 15
the total surface area of the first is simply 2(4x12) + 2(4 x 15) + 2(12 x 15)

576 sq units

the Second problem can be solved the same way.