+839 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?
+118609 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
$$\\A=\pi\times (2r)^2\\
A=\pi \times 2^2 \times r^2\\
A=4\pi r^2\quad cm^2\\$$
+11912 Rose do you know whats the formula to find the area of the circle , if so can u tell me?
+118609 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
$$\\A=\pi\times (2r)^2\\
A=\pi \times 2^2 \times r^2\\
A=4\pi r^2\quad cm^2\\$$
