Question

The radius of a circle is multiplied by 2. Its area is _____ times bigger than the original circle.

Answer 1

4

Answer 2

How'd you find that answer?

Answer 3

use the formula \[pir ^{2}\]

Answer 4

because area is 2*pi*r^2 ... if you increase r by 2 times then (2r)^2 = 4r^2 ... so increased by 4 times

Answer 5

now put 2r in the place of r, and u will find the answer

Answer 6

you can also look at an example....

what is the area of a circle radius 1?
what is the area of a circle radius 2? (double)

Answer 7

actually the area will be 4 times, but it will be 3 times greater than the previous circle