When the radius of a circle is multiplied by a factor of 3, by what factor will the circumference of the circle change? the circumference of a circle with radius 3 is (blank) times as big as the circumference of a circle with radius 1

The circumference of a circle with radius 3 is 3 times as big as the circumference of a circle with radius 1
Explanation:
Assume that the radius of the small circle is r
Increasing the radius by a factor of 3 means that the new radius of the large circle would be 3r

Circumference of circle can be calculated as follows:
circumference = 2*π*radius

For the small circle:
circumference = 2πr

For the large circle:
circumference = 2π(3r)
circumference = 6πr

Comparing the circumference of the two circles, we can deduce the increasing the radius by a factor of 3 will lead to the increase in the circumference of the circle by factor of 3 as well

Hope this helps :)