In order to calculate the sector area, we can use the following rule of three, knowing that an angle of 2pi (complete circle) has an area of pi*r² (area of the circle).
So we have:
[tex]\begin{gathered} \text{angle}\to\text{sector area} \\ 2\pi\to\pi r^2 \\ \frac{7\pi}{6}\to x \end{gathered}[/tex]Now, we can write the following proportion and solve the equation for x:
[tex]\begin{gathered} \frac{2\pi}{\frac{7\pi}{6}}=\frac{\pi r^2^{}}{x}^{} \\ x\cdot2\pi=\frac{7\pi}{6}\cdot\pi r^2 \\ x=\frac{\frac{7\pi}{6}\cdot\pi r^2}{2\pi} \\ x=\frac{7}{12}\pi r^2 \\ x=\frac{7}{12}\pi\cdot6^2 \\ x=\frac{7}{12}\pi\cdot36 \\ x=21\pi\text{ cm}^2 \end{gathered}[/tex]Therefore the sector area is 21pi cm².
