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.