If the radius of a circle is r cm, what is the area of the circle? If the radius is increased to 2r cm, what is the area of the circle?

Rose98 Sep 15, 2014

#1**+3 **

Rose do you know whats the formula to find the area of the circle , if so can u tell me?

rosala Sep 15, 2014

#2**+8 **

Best Answer

Rose, you can get the formula for the area of a circle on the from the formulary page on this site. It is

$$A=\pi r^2 \quad cm^2$$

Now if the radius is doubled it becomes 2r the new area will be

$$\\A=\pi\times (2r)^2\\

A=\pi \times 2^2 \times r^2\\

A=4\pi r^2\quad cm^2\\$$

Melody Sep 15, 2014