When the radius of a circle is multiplied by a factor of 3 by what factor will the circumference of the circle change?

When the radius of a circle is multiplied by a factor of 3, the circumference will also change by the same factor. The circumference ( C ) of a circle is calculated using the formula ( C = 2\pi r ), where ( r ) is the radius. Therefore, if the radius increases to ( 3r ), the new circumference will be ( C' = 2\pi(3r) = 3(2\pi r) ), thus increasing the circumference by a factor of 3.