Question Number 82392 by naka3546 last updated on 21/Feb/20
Commented by naka3546 last updated on 21/Feb/20
$${Area}\:\:{of}\:\:{shaded}\:\:{region}\:\:{is}\:\:… \\ $$
Commented by mr W last updated on 21/Feb/20
$${shaded}\:{area}=\frac{\pi{R}^{\mathrm{2}} }{\mathrm{4}}−\pi{r}^{\mathrm{2}} =\frac{\pi\left({R}^{\mathrm{2}} −\left(\mathrm{2}{r}\right)^{\mathrm{2}} \right)}{\mathrm{4}} \\ $$$$=\frac{\pi×\mathrm{12}^{\mathrm{2}} }{\mathrm{4}}=\mathrm{36}\pi \\ $$