Question

1. A rectangular pyramid is intersected by a plane to create the frustum shown. If the height of the original pyramid is 14 m, what is the volume of the frustum?
10 m
4 m
8 m
6 m
12m

Answer 1

The answer needs the volume of the original pyramid minus the small pyramid cut off.
Volume of pyramid = (area of base x height)/3
(12 x 6 x 14)/3 - (4 x 10 x 6)/3 = 256 m^3

The diagram is completely wrong so this problem is actually impossible to solve!
If you slice horizontally across a rectangular pyramid the ratios of the edges will remain constant.
The two rectangles are not the same shape! 12:6 is not the same ratio as 10:4

If the original pyramid in this question was sliced in half the top rectangle of the frustum would be 6 x 3.
In this diagram the height was reduced from 14m to 8m so the top 6m was removed.
If the base was 12 x 6 the top rectangle should be 6/14 smaller = 5.14m by 2.57m (not 10 x 4)

If you are brave you could point this out to your teacher