Hi Vipul, T is the point of intersection of the smaller circle and OC. I hope this makes the understanding of the solution clear.

Yeah, one can do that! There are numerous ways of solving a particular question.

Hi Bhavya,
Draw a perpendicular from C' on the lines CB and CD. The length of the perpendiculars will be 'r' . Thus CC' will be r$$\sqrt{2}$$

Hi Abhilash,

This is the easiest method to solve the problem.

Hi Mithun. Here we are talking about line segment CT, where T lies on the smaller circle and C lies on the rectangle. If we subtract OT from OC, we get CT. Also when we subtract TC' from CC', we will get CT. Hence we have equated the two.

Hi Akshay J Nair,
Yes, you are right. The answer $$2(\sqrt{2}-1)^4$$ : 1 is not given in the options of question. Whenever the answer is not given in the option, there will be an option none of the above(Here, option D) you will have to mark this as the right answer. When the given options don't contain the correct answer, you should always mark none of the above as your answer.
I hope this helps!

Hi Raj Vishnu,
Draw a perpendicular from C' on the lines CB and CD. The length of the perpendiculars will be 'r' (Radius of circle). Thus CC' will be $$r\sqrt{2}$$.
I hope this helps!