Answer: (b) 36 cm
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Work Shown:
r = radius = 7 cm
C = circumference of a full circle
C = 2*pi*r
C = 2*pi*7
C = 14*pi
C = 43.9822971502571 approximately
C = 43.9823
If we have a circle of radius 7, then the distance around the full circle is roughly 43.9823 cm.
Divide this over 2 to get the distance around half the circle
C/2 = 43.9823/2
C/2 = 21.99115
C/2 = 22 cm
This takes care of the curved portion. The straight portion is 2r = 2*7 = 14 cm which adds on to get 22+14 = 36 cm