A spiral is made up of successive semicircles, with centres alternately at A and B, starting with centre at A, of radii 0.5 cm. 1.0 cm. 1.5 cm, 2.0 cm as shows In fig. What Is the total length of such a spiral made up of thirteen consecutive semicircles? (Take \(\pi = \frac{22}{7}\))
[Hint: Length of successive semicircles is l1, l2, l3, l4 with centres at A, B, A. B respectively.]