Given, side of a square = 70 m
Also, four horses are tethered with equal ropes at 4 corners of the square field. Hence, each horse can graze upto 35 m of distance along the side.
Area of the square field = Side x Side
= 70 x 70
= 4900 m2
The grazed area is making a complete circle by taking all the four parts.
So, area of grazed part = πr2
= 22/7 x 35 x 35
= 22 x 5 x 35
= 3850 m2
Area left ungrazed by the horses = area of square field - Area of grazed part
= 4900 - 3850
= 1050 m2