. 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 inFig. 5.4. What is the total length of such a spiral made up of thirteen consecutive semicircles
Best Answer
Answer: Solution:Circumference of 1st semicircle = πr = 0.5π
Circumference of 2nd semicircle = πr = 1π = π
Circumference of 3rd semicircle =πr = 1.5π
It is clear that a = 0.5 π, d = 0.5π and n = 13
Hence; length of spiral can be calculated as follows:
= (7 )
= 13/2 x 7 x 22/7
= 143 cm
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