Q9 of 46 Page 73

On a square handkerchief, nine circular designs each of radius 7 cm are made. Find the area of the remaining portion of the handkerchief.

From the figure,



Hence, it can be observed that size of side of square = 14 + 14 + 14 = 42 cm


Area of square = (side)2


= 42 × 42


= 1764 cm2


Area of each circle = πr2



= 154 cm2


Area of 9 circles = 9 × 154


= 1386 cm2


Area of unshaded region = Area of square – Area of 9 circle


= 1764 -1386


= 378 cm2


More from this chapter

All 46 →
5

A cow is tied up for grazing inside a rectangular field of dimensions 40 m × 36 m in one corner of the field by a rope of length 14 m. Find the area of the field left ungrazed by the cow.

 6

A square park has each side of 100 m. At each corner of the park there is a flower bed in the form of a quadrant of radius 14 m as shown in the figure. Find the area of the remaining portion of the park.

 7

Find the area of the shaded region shown in the figure. The four corners are quadrants. At the center, there is a circle of diameter 2 cm.

 8

A paper is in the form of a rectangle ABCD in which AB = 20 cm and BC = 14 cm. A semicircular portion with BC as diameter is cut off. Find the area of the remaining part.