 In this problem, it's given that the radius of the given circle is 5 cm. You can see in the diagram, OR is perpendicular to PQ. PQ happens to be the chord. OC is perpendicular to AB. AB is the another chord. And PQ is parallel to AB. So two chords PQ and AB are parallel to each other. OR is perpendicular to PQ. Let me show it to you here. So OR is perpendicular to PQ and OC is perpendicular to AB. You have to find out the length of RC. So again, whatever we learned and did in the previous question, we'll have to do the same. So here, what is given? Radius of the circle, radius of circle is equal to 5 cm. AB is parallel to PQ. OR is perpendicular to PQ. And OC is perpendicular to AB. And it's given that AB is equal to 6 cm. And PQ is equal to 8 cm. To find, what do we need to find? We need to find RC. So how will you do it? So RC we have to find out, right? So again, if there are perpendicular dropped from the centers, obviously those perpendicular will bisect the chords. So hence we can say, solution. We can say, since OR is perpendicular to PQ, therefore, PR is equal to RQ. Reason being, perpendicular from center bisects the chord. This is the reason. Fair enough, right? Similarly, OC is perpendicular to AB. Therefore, what will happen? AC will be equal to CV. You can add one more information that it is 4 cm. And here it is 3 cm. Now, in triangle AOPR, since OR is perpendicular to PR, therefore, OP-square is equal to OR-square plus RP-square, isn't it? So OP-square is, so hence we can find out OR-square from here. It is nothing but OP-square minus RP-square. So it is equal to OP-square is how much? 5-square minus RP-square is equal to 4-square. You can check here. RP is 4. So hence it is, if you see 25 minus 16, which is 9 cm-square. So OR will clearly be 3 cm. Okay, OR is 3 cm. Now remember this. Next is, in triangle OAC, OA-square is equal to OC-square plus AC-square, why? Pythagoras theorem. Pythagoras theorem, right? So this is in the right-angle triangle, hypotenuse square is sum of squares of the other two sides, right? So hence, what is OC-square guys? OA-square minus AC-square. OA-square is how much? Radius-square, so 5-square. And AC-square is how much? AC-square is 3-square, right? So hence it is 16 minus 9, which is equal to, I'm sorry, 25 minus 9, not 16. So answer is there in my mind. So hence 25 minus 9, which is 16. So hence OC-square is 4 cm. Right? Now, what is RC? Clearly RC is OC minus OR. OC minus OR, what is OC? 4. And what is OR? 3. So hence it is 1 cm. Okay? Understood? Again, we applied two theorems here. One perpendicular from centre by 6th chord is 1. And another one is the Pythagoras theorem, which we have been using for many years now. Is that okay? So I hope you understood the problem and its solution.