The circumference of the two circles is 264 cm and 396 cm respectively. What is the difference between their radii?

21 cm 

Formula Used

Circumference = 2\(\Pi \)r

Difference in radius, r2 - r1 = C2/2\(\Pi \) - C!/2\(\Pi \)

Calculation

r2 - r1 = 1/2\(\Pi \) (C2 - C1)

= 1/2\(\Pi \) (396 - 264) cm

= (0.159 x 132) cm

= 20.99 cm

= 21 cm

Therefore, difference between the radii of two circles is 21 cm.