If the radius of a circle with an area of 12.56mm^2 is multiplied by s What is the area of the new circle?

Question

asked Aug 23, 2023 209k views

1 Answer

Egandalf · Answer 1 · 2023-08-28T13:09:33+0000

The Solution.

Let the radius of the original circle be r.

By formula,

$\begin{gathered} \text{Area =}\pi r^2 \\ 12.56=3.14r^2 \\ \text{Dividing both sides by 3.14, we get} \\ r^2=(12.56)/(3.14)=4 \end{gathered}$

Taking the square root of both sides, we get

$r=\text{ }\sqrt[]{24}\text{ = 2mm}$

For the new circle, the radius is multiplied by 5, that is,

$r=5r=5*2=10\operatorname{mm}$

So, the area of the new circle is

$\begin{gathered} \text{Area =}\pi r^2=3.14*10^2 \\ \text{ =3.14}*100=314mm^2 \end{gathered}$

Hence, the correct answer is 314 square mm.