Find thickness of a coin This is one of the question asked in a written test conducted by a company. The question sounded stupid to me. May be its not.
"Given the area of the coin to be 'A'. If the probability of getting a tail, head and the edge are same, what is the thickness of the coin?

I assumed that the probability of getting a head, tail or edge depended on the angle from the centre of the coin that the side lies in.  So the head, tail and edge must each occupy 120 degrees when viewed along the axis of rotation.

In the diagram above the angles at the centre are all (meant to be) 60 degrees and the radius of each face is $\sqrt{A/\pi}$.  A small amount of trigonometry later and I found the edge length to be $\sqrt{\frac{4A}{3\pi}}$.
