Trotting Horse

This task is about finding the circumference of a circle. 
horse-trotting-around-trainer.png
A horse trots around a track, on the end of a 10-metre rope, as a horse trainer stands in the centre.
 
 

Question 2Change answer

a)  Providing the rope remains fully stretched, how far does the horse travel
     when it trots once around the ring?
      m

Question 2Change answer

b)  The horse begins another full circle.
     This time it trots exactly half way around with the rope fully stretched at 10 metres.
     The trainer then moves towards the horse, shortening the rope to 6 metres.
     The horse then trots the second half of the circle.
     How far does the horse travel this time?
      m