Question

From a square cardboard of side 20 cm, a circle of maximum area is cut off. What is the area of the cardboard left out after removing the circle cut off? (Take $\pi =3.14$)

• A. 280 sq. cm.
• B. 100 sq. cm.
• C. 86 sq. cm.
• D. 480 sq. cm.

Answer 1

The correct option is C

86 sq. cm.

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 the square - Area of circle

= 400 - 314

= 86 sq. cm.