Question

What happens to a circle's circumference when the radius is doubled

Answer 1

The circumference doubles

Step-by-step explanation

Let the radius of the circle be r and the circumference be C.

The circumference of a circle is given as:

`C=2\pi r`

If the radius is doubled, the radius becomes:

`2r`

The circumference now becomes:

`\begin{gathered} C^(\prime)=2\pi\cdot(2r) \\ C^(\prime)=2\cdot(2\pi\cdot r) \\ C^(\prime)=2\cdot(2\pi r) \\ C^(\prime)=2C \end{gathered}`

Therefore, the circumference doubles when the radius is doubled.