 Hello and welcome to the session I am Deepika here. Let's discuss a question which says two concentric circles are of radii 5 centimeter and 3 centimeter, find the length of the cord of the larger circle which touches the smaller circle. Let us first recall the definition of concentric circles. Concentric circles are the circles which have the same center point. So this is a key idea behind the question. We will take the help of this key idea to solve the above question. So let's start the solution. Now we are given concentric circles C1 and C2 with center O and radii 5 centimeter and 3 centimeter respectively. That is O B is 3 centimeter and O B is 5 centimeter. We want to find the length of the cord of the larger circle that is C1 which touches the smaller circle that is C2 at the point D that is we want to find length of AB which touches the smaller circle G. A tangent is a line which touches the circle at only one point AB of larger circle touches the smaller circle at the point D the point of contact. Therefore T degree because the tangent at of a circle radius to the point of contact AB is equal to AB plus VD because the perpendicular of a circle we can say AB is equal to twice VD triangle ODB. So in right triangle AB we have by Pythagoras theorem VD is equal to O B square minus OD square or VD is equal to O B is 5 centimeter. So this is 5 square minus OD 3 centimeter 3 square VD is equal to the root of 25 minus and this is equal to root 16 and this is equal to 4. Hence VD is equal to 4 centimeter this implies AB is equal to 2 into 4 centimeter is equal to 8 centimeter because AB is equal to twice VD. Hence the length of the cord of the larger circle which touches a smaller circle is 8 centimeter. Hence the answer for the AB of question is 8 centimeter. I hope the solution is clear to you. Bye and take care.