Radius of circle, `=40/2` cm =20 cm

Now, OA=OB=20 cm and AB=20 cm

`rArr triangleOAB` is an equilateral triangle.

`therefore angleAOB=60^(@) = 60^(@) xx pi/180^(@)=pi/3` radian.

`therefore l = r.theta=20 xx pi/3 = 20/3 xx 22/7=440/21`

`rArr` Length of minor arc `=20.95` cm Ans.