Page 257 - ABCTE Study Guide_Neat

Now compute the formula for volume:

The volume of a pyramid is given by the formula , where B is the area of the base and h is the
height.

In other words, the volume of a pyramid is one-third of the volume of a prism with the same base and
height. Remember, base and height must be perpendicular.

Question

What is the volume of a pyramid wtih a base that measures 4 cm by 2 cm and a height of 5 cm? Round
your answer to the nearest tenth of a cubic centimeter.

3
A 29.3 cm

3
B 13.33 cm
3
C 93.6 cm

3
D 128.7 cm

Answer

Choice B is correct. The volume of the pyramid is given by the formula , where B is the area of the
base. So, first multiply 2 by 4 to get the area of the base (8). Then, multiply that value by the height (5) to
get 40. Divide this by 3 to get 13.33. If you answered C, you may have forgotten to multiply the product of
base and height by one-third.

Review

• The surface area of a three-dimensional figure is the sum of the areas of its faces.

• The volume of a prism is given by the formula , where B is the area of the base
and h is the height.

• The volume of a pyramid is given by the formula , where B is the area of the base
and his the height.