Find the area of both the segments of a circle of radius 42 cm with central angle 120°. [Given, sin 120° = √3/2 and √3 = 1.73.]

Given R = 42 cm and central angle of sector = 120°


Area of minor segment = Area of sector – Area of triangle eqn1



Where R = radius of the circle and θ = central angle of the sector




Area of sector = 1848 cm2


Area of right angle triangle = 1/2×base×height×sin θ


Where θ = central angle of the sector




Area of triangle = 1/2×42×42×√3/2


Area of triangle = (42×42×√3)/4


(put √3 = 1.73)



= 762.93 cm2


Put the values of area of triangle and area of sector in equation 1


Area of minor segment = 1848 – 762.93


= 1085.07 cm2


Area of major segment = πR2 – Area of minor segment


Put the value of area of minor segment and R in above equation


= π(422) – 1085.07


Area of major segment = 22/7×42×42-1085.07


(put π = 22/7)


Area of major segment = 5544 – 1085.07


Area of major segment = 4458.93 cm2


Area of major segment is 4458.93 cm2 and of minor segment is 1085.07 cm2.


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