The length of the rope with which the horse is tied becomes the radius of the circular area.
Length of rope = 5 m
Area within which the horse can graze
= pi * r^2 = 3.14 * 5 = 15.7 m^2
Area of the grassland at the Centre of which the horse is tied = 3.14 * 25
= 78.5 m^2
Area in which the horse cannot graze
= Area of grassland - Area in which the horse can graze
= 78.5 - 15.7
= 61.8 m^2
