Everything Maths Grade 11

(Marvins-Underground-K-12) #1

CHAPTER 16. GEOMETRY 16.2


Volume of a Pyramid: The volume of a pyramid is found by:


V =

1


3


A. h

where A is the area of the base and h is the perpendicular height.


A cone is like a pyramid, so the volume of a cone is given by:


V =

1


3


πr^2 h.

A square pyramid has volume


V =

1


3


a^2 h

where a is the side length of thesquare base.


See video: VMfqj at http://www.everythingmaths.co.za

Example 2: Volume of a Pyramid


QUESTION

What is the volume of asquare pyramid, 3 cm high with a side length of 2 cm?

SOLUTION

Step 1 : Determine the correctformula
The volume of a pyramid is

V =


1


3


A. h,

where A is the area of the base and h is the height of the pyramid. For a square
base this means
V =

1


3


a. a. h

where a is the length of the sideof the square base.

2 cm^2 cm

3 cm

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