Wed March 28, 2012 By: Minu Joseph

A cow is tethered to a corner of a field with a rope of length 7 m. If she grazes on the length of 210 m , what is the angle through which the rope moves? A. 45 degrees B. 30 degrees C. 60 degrees D. 90 degrees Correct Correct Answer: B how is this possible ?

Expert Reply
Wed March 28, 2012
We know that in a circle of radius r units, if an arc of length l units subtends an angle theta radian at the centre, then theta = l/ r.

Here, r = 7 m (length of rope will be equal to radius) and l = 210 m (length of arc will be the length which the cow grazed)
Thus, theta = 210/ 7 radians = 30 radians
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