VOLUME – VOLUME OF PRISMS, CYLINDERS AND SPHERES

Back to: Mathematics Primary 6

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The figure above is a prism. Prisms have different types of base. Hence, we have triangular based prism, a rectangular based prism etc. formula for calculating volume of prism is

V = Bh. (where B is the area of the base of the prism)

 

Cylinder: A cylinder has a circular base.

 V = 𝝅r² h (Area of circle x height)

 

Sphere

Examples:

The base of a right prism is a triangle whose sides are of lengths 9 cm. 10 cm. and 11 cm. Find the volume and total surface area of the prism if its height be 15 cm.

Solutions

Volume = area of triangle x height(length)

= ½ x b x h x l

= ½ x 10 x 9 x 15

= 675sqcm

ACTIVITY

Find the volume of the prisms below

   

Example:

Activity

1. Calculate the volume of a cylinder where:

1. a) the area of the base is 30 cm 2 and the height is 6 cm.
2. b) the radius of the base is 14 cm and the height is 10 cm.

1. Find the volume of cylinder with radius of 5.5 feet and a height of 11.4 feet.
2. Find the volume of cylinder with diameter of 12 inches and a height of 29 inches.
3. The figure shows a section of a metal pipe. Given the internal radius of the pipe is 2 cm, the external radius is 2.4 cm and the length of the pipe is 10 cm. Find the volume of the metal used.

 

Example: Calculate the volume of sphere with radius 4 cm.

Solution:

Volume of sphere

ACTIVITY

1. The volume of a spherical ball is 5,000 cm3. What is the radius of the ball?

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