Question

If the radius of a circle is doubled, how does the area of the circle change?

Hint: find the area of a circle with r=2 & r=4; compare answers.

Answer 1

if the radius of a circle is doubled, the area of the circle is quadrupled.
area of a circle = 2(pi)(radius)^2
when r = 2, area = 8pi
when r = 4, area = 32pi
you can see that the area is quadrupled