Question Number 140276 by cherokeesay last updated on 06/May/21
Answered by mr W last updated on 06/May/21
Commented by mr W last updated on 06/May/21
$$\alpha=\mathrm{60}°−\mathrm{45}°=\mathrm{15}°=\frac{\pi}{\mathrm{12}} \\ $$$$\frac{{A}}{\mathrm{2}}=\frac{\mathrm{10}^{\mathrm{2}} }{\mathrm{2}}×\frac{\pi}{\mathrm{12}}−\frac{\mathrm{5}×\left(\sqrt{\mathrm{10}^{\mathrm{2}} −\mathrm{5}^{\mathrm{2}} }−\mathrm{5}\right)}{\mathrm{2}} \\ $$$$\Rightarrow{A}=\frac{\mathrm{25}\pi}{\mathrm{3}}−\mathrm{25}\left(\sqrt{\mathrm{3}}−\mathrm{1}\right) \\ $$
Commented by cherokeesay last updated on 06/May/21
$${very}\:{nice}\:! \\ $$$${thank}\:{you}\:{sir}\:! \\ $$