Question

A circle with radius of 1cm sits inside a 3cm x 4cm rectangle.What is the area of the shaded region?

Answer 1

$\bf \stackrel{\textit{area of a rectangle}}{A=Lw}\qquad \qquad \stackrel{\textit{area of a circle}}{A=\pi r^2} \\\\\\ \stackrel{\textit{area of the rectangle}}{(3\cdot 4)}~~~~-~~~~\stackrel{\textit{area of the circle}}{[\pi (1)^2]}~~~~=\textit{shaded area} \\\\\\ 12-\pi =\textit{shaded area}\implies 8.86\approx \textit{shaded area}$