Question

From a square cardboard of side 20 cm, a circle of maximum area is cut off. The area of the cardboard left out is ___ sq. cm. (Take $\pi =3.14$)

• A. 480
• B. 200
• C. 100
• D. 86

Answer 1

The correct option is D

86

The diameter of the circle = side of the square

= 20 cm

$\therefore$ r = 10 cm

Area of circle $=\pi r^2$

$=3.14\left(100\right)$

$=314\text{sq.cm}$

Area of square $=sid{e}^2$

$=(20{)}^2$

= 400 sq. cm

Area of cardboard left out = Area of square - Area of circle

= 400 - 314

= 86 sq. cm.