A horse is tied to a post by a rope. If the horse moves along a circular path always keeping the rope streched and describes 88 metres when it has traced out 72° at the centre, the length of the rope is ( Take = 227 )

Answer: Option A

Solution

Answer: Option A

Solution:

$$\begin{array}{rl}& \text{Length of arc}=\frac{\theta }{360}\times 2\pi r\\ & \frac{72}{360}\times 2\times \frac{22}{7}\times r=88\\ & r=\frac{88\times 7\times 360}{72\times 2\times 22}\\ & r=70\text{ m}\end{array}$$