A chord of a circle of radius 15 cm subtends an angle of 60° at the centre. Find the areas of the corresponding minor and major segments of the circle
(Use π = 3.14 and = 1.73)
Radius (r) of circle = 15 cm
Area of sector OPRQ = (60/360)×Πr2
= ×3.14 × (15)2
= 117.75 cm2
In ΔOPQ,
∠OPQ = ∠OQP (As OP = OQ)
∠OPQ + ∠OQP + ∠POQ = 180°
2 ∠OPQ = 120°
∠OPQ = 60°
ΔOPQ is an equilateral triangle.
Area of ΔOPQ = ×(Side)2
= × (15)2
=
= 56.25 ×
= 97.3125 cm2
Area of segment PRQ = Area of sector OPRQ - Area of ΔOPQ
= 117.75 - 97.3125
= 20.4375 cm2
Area of major segment PSQ = Area of circle - Area of segment PRQ
= Π(15)2 – 20.4375
= 3.14 ×225 – 20.4375
= 706.5 – 20.4375
= 686.0625 cm2