Q:

The composite figure is made up of two congruent rectangular pyramids joined at their bases. What is the total volume of the composite figure? units3

Accepted Solution

A:
The total volume of the composite figure is the sum of the volumes of the two rectangular pyramides. Given the two rectangular pyramids are congruent then their volumes are equal and the total volume is twice the volume of one pyramid.

The volume of one pyramid is the area of the base * height * 1/3

So, the total volume of the composite figure is:

 2 * 1/3 * area of the base * height.

The base is a rectangle of sides 2 units and 7.5 units, so its area is 2 units *7.5units = 15 units^2

The height of one pyramid is 6 units.

So, the total volume of the composite figure is 2 * (1/3) * 15 unit^2 * 6 unit = 60 unit^3.

Answer: 60 unit^3