A cow is tied with a rope of length 14 m at the corner of a rectangular field of dimensions 20 m × 16 m. Find the area of the field in which the cow can graze.
Let ABCD be a rectangular field.
Length of field = 20 m
Breadth of the field = 16 m
Suppose a cow is tied at a point A.
Let length of rope be AE = 14 m = l (say).
Angle subtended at the center of the sector = 90°
Angle subtended at the center (in radians) θ = 90π/180 = π/2
∴ Area of a sector of a circle
= 154 m2
Hence, the required area of a sector of a circle is 154 m2.