Question

In the given figure, OACB is a quadrant of a circle with centre O and radius 3.5 cm If OD = 2 cm, find the area of the

(i) quadrant OACB,

(ii) shaded region.

Answer 1

Radius of Circle, OA = OB = 3.5 cm.

OD = 2 cm.

(i) Area of quadrant of a circle

(ii) Area of the shaded region

(i) Area of quadrant (OACB) of a Circle

r = 3.5 cm, θ = 90°

(ii) In ⊥∆BOD, ∠BOD = 90°

OB = 3.5 cm; OD = 2 cm

∴ Area of shaded region,

= Area of quadrant OACB – Area of ABOD

= 9.61 – 3.5

= 6.11 sq.cm.