Question

if the circumference of two concentric circles forming the ring are 88cm and 66cm find the width of the ring?

Answer 1

Let the radius of the two concentric circles be R and r respectively.
Now,
Circumference of the bigger circle = 2*pi*R
=> 88 = 2 * 22/7 * R
=> 88*7/2*22 = R
=> R = 4*7/2
=> R = 14 cm
Then,
Circumference of smaller circle = 2*pi*r
=> 66 = 2* 22/7 * r
=> 66*7/2*22 = r
=> r = 3*7/2
=> r = 1.5*7
=> r = 10.5 cm
Hence, Width of the Ring = R - r
=> width of the ring = 14 - 10.5
=> Width of the ring = 3.5 cm Ans...