Find the area of the shaded region in Fig. 12.20, if radii of the two concentric circles with centre O are 7 cm and 14 cm respectively and AOC = 40°.


Area of the shaded region = Area of Bigger sector –area of Smaller Sector

If R and r are the two radii of Bigger and Smaller circles respectively, then:


Area of shaded region = 22 )


= 22 )


= 51.33 sq cm


2
1