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

Diameter of the circle=40cm∴Radius (r) of the circle=40/2=20cm
Let AB be a chord (length = 20 cm) of the circle.
In△OAB, OA = OB = Radius of circle = 20 cm
Also, AB = 20 cm
Thus,△OABis an equilateral triangle.
∴θ=60∘=π/3 radian
We know that in a circle of radius r unit, if an arc of length l unit subtends an angle θ radian at the centre, then
θ=l/r
∴π/3=arc AB/20
⟹arc AB=(20π)/3cm