1. The rectangular prism is a right prism with rectangular bases (check the picture)
2. It has 8 vertices, so we are looking for 3d figures with 4 vertices.
3. A face can have at least 3 vertices, and the 4th must be outside of the plane determined by the first 3 vertices. This makes 4 vertices in total.
4. The 3d figure described in step 3 is a pyramid.
According to your description, you can simply plug in all the numbers:
d(47) = 2.15 * 45^2 / (58.4*0.34) = 219.27 m
S.F. of 9/24 = 3/8
S.F. of 14/24 = 7/12
S.F. of 10/15 = 2/3
S.F. of 10/12 = 5/6
S.F. of 18/27 = 2/3
S.F. of 10/15 = 2/3
Hope this helps!