Question

answer this question.................

Answer 1

distance=D=diameter
distance/speed=time
semicircle perimeter=πd/2
diameter=D
speed =60m/min
$\frac{d\pi}{2 \times 60} - \frac{d}{60} = 3 \\ d( \frac{\pi}{120} - \frac{2}{120} ) = 3 \\ d = \frac{360}{\pi - 2} \\ d = \frac{360}{8} \times 7 \\ d = 315$