Question

I. A circular carpet of diameter 1.4 m is spotted in the centre with a 20 cm striped border. Find the area of the striped portion of the carpet to the nearest cm.​

Answer 1

Answer:

Let 1.4 m=140 cm

Radius =

2

140

=70 cm

Extra strip is of diameter

=20 cm/2.

Radius =10 cm

∴ Radius for outer circle

=80 cm

Area of that path or strip

=

7

22

×R

2

−

7

22

×r

2

=

7

22

(R

2

−r

2

)

=

7

22

(80+70)(80−70)

=

7

22

×150 cm×10 cm

=

7

33000

cm

2