Question

the circumference of a circle is 40TT what is the radius

Answer 1

The circumference of a circle is given by the following formula:

$c=2\pi r$

From this equation, we can solve for r by dividing both sides by 2π, like this:

$\begin{gathered} \frac{c}{2\pi}=\frac{2\pi r}{2\pi} \\ \frac{c}{2\pi}=\frac{2\pi}{2\pi}r \\ \frac{c}{2\pi}=1\times r \\ \frac{c}{2\pi}=r \\ r=\frac{c}{2\pi} \end{gathered}$

By replacing 40π for c, we get:

$r=\frac{40\pi}{2\pi}=20$

Then, the radius of the circle equals 20