Question

If the area of a circle is numerically equal to twice its circumference, then what is the diameter of the circle ?

Answer 1

Let the radius of the circle = r units
area of the circle = 2 $\times$ circumference

$\pi$$r^2$ = 2(2 $\pi$ r)
$\frac{r^2}{r}$ = 4$\frac{\pi }{\pi }$
r=4
diameter = 2r
d=2$\times$4
d=8units