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 shown in figure. What is the total length of such a spiral made up of thirteen consecutive semicircles?
(Take π = 22/7)
[ Hint: Length of successive semicircles is l1, l2, l3, l4, … with centres at A, B, respectively.]
