Buffon’s needle problem – Wikipedia

In mathematics, Buffon’s needle problem is a question first posed in the 18th century by Georges-Louis Leclerc, Comte de Buffon:. Suppose we have a floor made of parallel strips of wood, each the same width, and we drop a needle onto the floor. What is the probability that the needle will lie across a line between two strips?. Buffon’s needle was the earliest problem in geometric probability …

https://en.wikipedia.org/wiki/Buffon%27s_needle_problem