"Published in Vacaville, California, USA"
A dam is 40 ft. long, 12 ft. high, 7 ft. wide at the bottom, and 4 ft. wide at the top. How many cubic yards of material were used in constructing it?
Solution:
To illustrate the problem, it is better to draw the figure as follows
![]() |
Photo by Math Principles in Everyday Life |
The area of the base which is the area of the cross section of a trapezoid prism is
Therefore, the amount of material used in constructing a dam which is the volume of trapezoid prism is
or