Math 8 / Volume of Cylinders

Formula

100

What formula do we use to find the volume of a cylinder?

V=πr2h

200

If the diameter is 12 , what is the radius?

r = 12/2 = 6

Solve It

100

Find the volume :

Radius = 2

Height = 5

V = 3.14 ( \(2^{2}\)) (5)

V = 3.14 (4)(5)

V= 62.8

200

Radius = 3

Height = 4

V = 3.14 (3²) (4)

V= 3.14 (9) (4)

V = 113.04

Common Mistakes

100

What is the mistake ?

V = 3.14 (8²) (5)

If 8 is the diameter

They used the diameter instead of dividing by 2 to get the radius.

Correct Radius = 4

200

What mistake did the student make?

V = 3.14 (4) (6)

They forgot to square the radius 

Correct = V= 3.14 (4²) (6)

Vocabulary

100

What does Volume measure?

The amount of space inside a 3D object.

200

What is a cylinder?

A 3D shape with two circular bases and one curved surface.