Question

What is the shaded value?

Answer 1

`\textit{area of a circular ring}\\\\ A=\pi (R^2-r^2) ~~ \begin{cases} R=\stackrel{outer}{radius}\\ r=\stackrel{inner}{radius}\\[-0.5em] \hrulefill\\ R=\stackrel{10+1}{11}\\ r=10 \end{cases}\implies A=\pi (11^2-10^2)\implies A\approx 66.0`