Question

If the diameter of a circle with a circumference of 22.75 inches is doubled, what would be the circumference of a new circle

Answer 1

Let's solve this probem in general, to understand the underlying concept.

The circumference of a circle, knowing its radius, is given by

`C = 2\pi r`

So, if the radius is doubled, we map
`r \mapsto 2r` and the circumference becomes

`C' = 2 \pi (2r) = 2 (2 \pi r) = 2C`

So, if you double the radius, the circumference doubles as well, and so it becomes

`22.75 \mapsto 45.5`