Given,
Length of the string (l) = 28 m
Area the horse can graze is the area of the circle with a radius equal to the length of the string.
We know that,
Area of a Circle = πr2
= (22/7) × 28 × 28 = 2464 m2
Hence, the area of the circle which is same as the area the horse can graze is 2464 m2