Refer to Fig. 5.4. The drawing shows a spiral made of successive semicircles with centres alternating at A an…

Refer to Fig. 5.4. The drawing shows a spiral made of successive semicircles with centres alternating at A and B, and radii 0.5, 1.0, 1.5, ... cm. Find the total length of the spiral made up of thirteen consecutive semicircles. (Use $\pi =22/7$.) [Hint: Length of semicircles is $l_1,l_2,l_3,l_4,\dots$.]