Find the angle in radians through which a pendulum swings if its length is 75 cm and the tip describes an arc of length (i) 10 cm (ii) 15 cm (iii) 21 cm.
Given radius = 75 cm
We know that 
(i) Given length of arc = 10 cm
(ii) Given length of arc = 15 cm
(iii) Given length of arc = 21 cm
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