 Hi and welcome to the session. Let us discuss the following portion together which says in a circle of diameter 40 cm the length of the cord is 20 cm. Find the length of the minor arc of the cord. So let us begin with the solution and let us interpret the above portion diagrammatically. We are given a circle of diameter 40 cm so this hole is 40 cm. Also we are given that there is a cord of 20 cm so let this be a cord which is 20 cm and we have to find the minor arc of the cord that is we are required to find the length of this arc. Let the cord be denoted by AB and here we are given that diameter of circle is equal to 40 cm therefore radius will be equal to 40.2 that is 20 cm and let O be the same term and then join OB. Now let us draw perpendicular from O on the cord AB then it will bisect the cord and let this point be denoted by D then in triangle ODB OB upon DB which is equal to H upon P which is further equal to this OB is equal to 20 cm being the radius of the circle and P which is DB is 10 cm since DB is equal to half of AB and this is because ODB is perpendicular on AB this implies OB bisects cord AB is equal to 2 and H upon P is equal to coset theta this implies theta is equal to is equal to 30 degree this is from here. Now angle is theta which is 30 degree therefore this whole angle that is angle AOB which is 2 times of angle DOB will be equal to 2 into 30 that is 60 degree and hence angle AOB is equal to 60 degree length of an R is equal to 2 pi R into the angle which the arc subtends at the centre divided by 360 which is equal to 2 pi R into angle AOB upon 360 which is further equal to 2 into pi radius of the circle is equal to 20 cm into angle AOB is 60 degrees upon 360 0 cancels output 0 and we have 6 into 6 36 2 3s are 6 so we have 20 pi upon 3 and therefore we can say that length minor arc the chord is equal to 20 upon 3 pi so this completes the solution hope you enjoyed the session take care and bye for now.