Question

find the area between two circular rings if the radio are 10.5 cm and 3.5 cm (use =22\7​

Answer 1

Answer:

Let the radii of the outer and inner circles be r

2

and r

1

respectively; we have

Area=πr

2

2

−πr

1

2

=π(r

2

2

−r

1

2

)

=π(r

2

−r

1

)(r

2

+r

1

)

=π(5.7−4.3)(5.7+4.3)=π×1.4×10 sq. cm

=3.1416×14sq.cm.=43.98 sq. cm