Question No. 2876 (Adapted from ScienceNet):

What is "pi"? What does it stand for?

In mathematics, "pi" is defined as the ratio between the circumference of a circle and its diameter(pi = circumference / diameter).

You may find Ask Dr. Math. interesting.

Some of the interesting mathematics questions posted at ScienceNet

Question No. 14317 :Why are there 360 degrees in a circle? Why not say 100 degrees?

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Question No. 19863 :How is radian useful in our daily lives? Why can't degree always be used?

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Mr Sun: what do you notice about the change in the shape of the polygons?