Question

a horse is tied to a pole with 21 m long string find the area where the horse can graze
and the answer is 1386 m square

Answer 1

a horse can possibly travel equal distance from the pole to any direction
which can possibly form a circle with radius of length 21 m

Then the area covered by it is equal to area of the circle with 21m radius
Area =pi*21*21 = pi * r^2

Area = 1385.44 ~1386 square meter

Answer 2

if a horse is tied to string of 21m he can graze and make an area of round circle with radius (r)=21m.

we know that ,
area of circle=πr^2
=22/7*21*21
=22*3*21
=1386m^2