Question

If the radius of a circle is multiplied by 2, then how many times larger is the circumference of the new circle?

2.

4.

8.

pi.

Answer 1

C = 2*pi*r , so if r is doubled the new C is 2*pi*2r , so it is 4pi.

Answer 2

well 2 times larger.

Answer 3

haha not quite, its just doubled. if r is double the circumference is doubled. so its just 2 times larger.

Answer 4

I got it now, thanks! :)

Answer 5

If it asks for area, the equation is \[\pi*r^2 \] so when its doubled the area quadruples. (4x times larger)