Find the circumference of the circles whose radii are given below

Matching exercise

    
Match the items on the right to the items on the left.
r = 49cm
r = 91 cm
r = 70cm
r = 56 cm
r = 28 cm
circumference = 308 cm
circumference = 572 cm
circumference = 440 cm
circumference = 352 cm
circumference = 176 cm