Question

The radius of a circle is 2 kilometers. What is the area of a sector bounded by a 90° arc?

Answer 1

`\textit{area of a sector of a circle}\\\\ A=\cfrac{r^2\theta \pi }{360}~~ \begin{cases} r=radius\\ \theta =\stackrel{degrees}{angle}\\[-0.5em] \hrulefill\\ r=2\\ \theta =90 \end{cases}\implies A=\cfrac{(2)^2(90)\pi }{360}\implies A=\pi`