Video Transcript
A cylinder has a radius of nine
centimeters and a height of 14 centimeters. Work out the volume of the
cylinder, giving your answer in terms of 𝜋.
Let’s begin by recalling how we
calculate the volume of a cylinder. The formula we use is 𝜋𝑟 squared
ℎ, where 𝑟 represents the radius and ℎ the height of the cylinder. In applying this formula, we’re
calculating the area of the cylinder’s circular cross section, and then multiplying
this by its height.
We’re given that the radius of this
cylinder is nine centimeters and the height is 14 centimeters, so we can substitute
both values into the formula. Doing so gives that the volume is
equal to 𝜋 multiplied by nine squared multiplied by 14.
Now, we could type this into a
calculator and evaluate the answer as a decimal, but the question specifies that we
should give our answer in terms of 𝜋. So instead, we’ll just evaluate
nine squared multiplied by 14. Nine squared is 81, and 81
multiplied by 14 is 1,134. The volume of the cylinder is
1,134𝜋 cubic centimeters.
