Question

find the area of the corresponding major sector of a circle of radius 28cm and central angle 45

Answer 1

Dear student
$$\begin{gathered} \mathrm{Area}\mathrm{of}\mathrm{sector}=\frac{\mathrm{\theta }}{360°}\times {\mathrm{\pi r}}^2 \\ =\frac{45°}{360°}\times \frac{22}{7}\times 28\times 28 \\ =308{\mathrm{cm}}^2 \\ \mathrm{Area}\mathrm{of}\mathrm{circle}={\mathrm{\pi r}}^2 \\ =\frac{22}{7}\times 28\times 28 \\ =2464{\mathrm{cm}}^2 \\ \mathrm{Area}\mathrm{of}\mathrm{major}\mathrm{sector}=\mathrm{Area}\mathrm{of}\mathrm{circle}-\mathrm{Area}\mathrm{of}\mathrm{sector} \\ =\left(2464-308\right){\mathrm{cm}}^2 \\ =2156{\mathrm{cm}}^2 \end{gathered}$$
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