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