In Figure, arcs have been drawn of radius 21 cm each with vertices A, B, C and D of quadrilateral ABCD as centres. Find the area of the shaded region.
Area of sector =
Here
Radius = 21 cm
There are four sectors in the figure
Area of sector =
=
Area of shaded region = 4 × Area of one sector
= 4 × 346.5
= 1386 cm2