[tex]\bf \textit{area of a segment of a circle}\\\\ A=\cfrac{r^2}{2}\left(\cfrac{\pi \theta }{180}-sin(\theta ) \right)~~ \begin{cases} r=&radius\\ \theta =&angle~in\\ °rees\\ \cline{1-2} r=&3\\ \theta =&\stackrel{radians}{\frac{2\pi }{3}}\\ &\stackrel{degrees}{120} \end{cases} \\\\\\ A=\cfrac{3^2}{2}\left(\cfrac{\pi (120) }{180}-sin(120^o) \right)\implies A=\cfrac{9}{2}\left(\cfrac{2\pi }{3}-\cfrac{\sqrt{3}}{2} \right) \\\\\\ A \approx \cfrac{9}{2}(1.23)\implies A\approx 5.535[/tex]
