Question

From a rectangular sheet of paper ABCD with AB = 40 cm and AD = 28 cm, a semicircular portion with BC as diameter is cut off.Find the area of the remaining paper.

Answer 1

First find the ar of the rectangle ABCD
=28*40
=1120
then fimd the ar of semicircle=$\frac{1}{2}ofcircle$
=quadrant OAPC =$\pi \frac{r^2}{4}=\frac{1}{4}\times \frac{22}{7}\times 7\times 7=308{cm}^2$

then subtract=arof ABCD-ar of semi cirlcle
=1120-308
=$812{cm}^2$
this is the remaining area of paper