Q.

An arc of a circle of radius 21 cm subtends an angle of 60o at the centre. Find the area of the minor segment of the circle made by the corresponding chord.


Ans.

In ∆OAB, OA = OB = 21cm

⇒ ∠OAB = OBA = 60o

(∵ ∠AOB = 60o and angles opposite to equal sides & Angle sum property of triangle)

Thus, ∆OAB is equilateral triangle.

Area of the minor segment = Area of sector OAB – Area of triangle of OAB

=θ3600×πr2-34a2=6003600×227×21×21-34212

=231-44134 cm2