Question

A cylinder is filled with 900 liters of water.find the area of its base if height of cylinder is 20dm.

Answer 1

The formula of the volume of a cylinder:

$V=\pi r^2H\\\\where:\\\\r-a\ radius\\H-a\ height\\\pi r^2-an\ area\ of\ base$

We have:

$V=900\ liters\\1L=1dm^3\ therefore\ V=900L=900dm^3$

and

$H=20\ dm$

substitute:

$\pi r^2\cdot20=900\ \ \ |:20\\\\\pi r^2=45\ dm^2$

Answer: The area of a base of the cylinder is equal 45 dm².