are of shaded region = area of circle - area of segment
[tex] = \pi {r}^{2} - ((\alpha \div 360) \times \pi \times {r}^{2} )[/tex]
[tex] = \pi {r}^{2} (1 - \alpha \div 360)[/tex]
[tex]r = 8.35 \\ \alpha = 100[/tex]
[tex] = 158.1666.... [/tex]
[tex]rounding \: up[/tex]
[tex]area \: of \: shaded \: region \: = 158.2 \: \: square ft [/tex]
