Find the easiest solution of ncert class 10th question of areas related to circles give me the best solution of exercise 12.3 question no. 2. Sir please help me to solve this question.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°.
Given,
Angle made by sector = 40°,
Radius the inner circle = r = 7 cm, and
Radius of the outer circle = R = 14 cm
We know,
Area of the sector = (θ/360°)×πr2
So, Area of OAC = (40°/360°)×πr2 cm2
= 68.44 cm2
Area of the sector OBD = (40°/360°)×πr2 cm2
= (1/9)×(22/7)×72 = 17.11 cm2
Now, area of the shaded region ABDC = Area of OAC – Area of the OBD
= 68.44 cm2 – 17.11 cm2 = 51.33 cm2