Question

A circular of radius 4 cm is cut out from square cardboard of a side of 10 cm. What is the area of the leftover cardboard? (Take π=3.14)

Answer 1

Answer:

$r=4cm, a=10cm \\ Therefore, \: the \: area \: of \: the \: leftover \: cardboard \: is \\ =Area \: of \: square-Area \: of \: circle \\ =a²-πr² \\ =(10)²-( \frac{22}{7} )(4)² \\ =100- \frac{22}{7} ×16 \\ = 100 - \frac{352}{7} \\ = \frac{700 - 352}{7} \\ = \frac{348}{7} {cm}^{2} \\ = 49.71 {cm}^{2}$