Question

The width of a ring whose outer and inner radii are 21cm and 17.5 cm, is _____ cm.
PLZ I NEED IT AS FAST AS POSSIBLE....

Answer 1

Answer:

Let the radius of the circles be r

1

​

 and r

1

​

Area of the outer circle

   πr

1

​

 

2

=1386

=>r

1

​

 

2

=

22

1386×7

​

=>r

1

​

=21cm

Area of inner circle-

=>πr

2

2

​

=962.5

=>

7

22

​

×r

2

2

​

=962.5

=>r

2

2

​

=

22

962.5×7

​

=>r

2

​

=17.5cm

Width of the ring=r

1

​

−r

2

​

=21−17.5=3.5

Step-by-step explanation: