Question

If a cylinder holds a volume of 100 cm3, and is 30 cm tall, which is the area of the bottom of the cylinder?

Answer 1

=πr2h


Area of circle
=πr2

=V/h
=100/30
≈3.33cm

Answer 2

Well, lets break this down.

Volume = area of base * height

we know that the volume is 100 and the height is 30 so we can work backwards

100 = b * 30

now divide both sides by 30

(100/30) = b * (30/30)

the height cancels itself out and we are left with...

base = 3.33

therefore your answer is 3.33 cm^2