Question

A person looking through telescope just sees the point on the rim at the bottom of a cylindrical vessel which is empty. when the vessel is completely filled with a liquid, he observes a mark at the centre bottom without moving the telescope or the vessel. the diameter of the base of the vessel is . the height of the vessel is :

Answer 1

It is not solved by me.. it's solved by my frnd as I don't know how to solve it. Hope u understand.