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


Given: A circle of diameter 40 cm radius = 20cm


The length of a chord is 20 cm.



Here, we can see that, the figure forms a equilateral triangle with side length 20 cm


(both radii = 20cm and length of chord = 20cm)


AOB = 60° ( Angles in an equilateral triangle are 60° each)


60° = 60 × = radians


That is, The Chord AB makes radians at the centre of the circle.


Now, We know that θ = (here, θ is angle subtended by arc)



l =


Length of the arc AB is cm.


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