Question

In a circle of diameter 40 cm, the length of a chord is 20 cm. Find the length of minor arc of the chord.  

Answer 1

Let ‘O’ be the centre of the circle and AB be the chord of the circle. Here, d = 40 cm

∴ r = 40/2 = 20 cm

Since OA = OB = AB, 

∆OAB is an equilateral triangle. 

The angle subtended at the centre by the minor 

arc AOB is θ = 60° = (60 x π/180)^c = (π/3)^c 

= l(minor arc of chord AB) = rθ = 20 x π/3)

= 20π/3 cm