Question

find the area of quadrant of circle which diameter is 7 cm​

Answer 1

$diameter (d)= 7 \: cm \\ \\ radius(r) = \frac{d}{2} = \frac{7}{2} \: cm \\ \\ area \: of \: one \: quadrant \: of \: circle = \frac{1}{4} \times area \: of \: circle \\ \\ = \frac{1}{4} \pi {r}^{2} \\ \\ = \frac{1}{4} \times \frac{22}{7} \times {( \frac{7}{2} )}^{2} \\ \\ = \frac{1}{4} \times \frac{ \cancel{22}}{ \cancel{7} } \times \frac{ \cancel{7}}{ \cancel{2} } \times \frac{7}{2} \\ \\ = \frac{77}{8} \\ \\ \underline {\underline{{= 9.625 \: {cm}^{2}} }}\\ \\ \\ \\ \underline{\boxed{\sf{ area \: of \: quadrant \: of \: circle = 9.625 \: {cm}^{2} }}}$