What is the name of the number used to measure the circumference of a circle?

Pi (π)

The anecdote related to this question highlights the historical and conceptual importance of the number π in mathematics. Since antiquity, mathematicians have sought to understand the relationship between the circumference and the diameter of a circle. However, the true irrational and infinite nature of π was discovered later, leaving even the brightest minds in the history of mathematics perplexed. This constant has inspired fascinating mysteries and conjectures, and its presence in numerous scientific and natural domains attests to its universal importance. Through the centuries, π has become a symbol of the quest for knowledge and the beauty of mathematics, illuminating our understanding of the world around us.