Question

Find the area of sector of a circle of radius 28cm and central angle 45degree

Answer 1

area of the circle is =
$\pi \times {r}^{2}$
angel is 360°

if we cut circle across the diameter then
it will be semicircle then area of it will be
$\frac{1}{2 } \times \pi \times {r}^{2}$
angel is 180°

if we cut the semicircle from the middle then the area of the sector will be
$\frac{1}{4} \times \pi \times {r}^{2}$
angel is 90°

if cut again the above sector from middle then the area of new sector will be
$\frac{1}{8} \times \pi \times {r}^{2}$
and the angel is 45°

so calculate it by the above formula....