The ratio of the dimensions of the base of the Egyptian pyramids to their height includes pi as a factor. I once saw a TV show that concluded that since there's no evidence the Egyptians knew what pi was, space aliens must have been involved in their construction.
Later, some wag pointed out that if one uses a measuring wheel one cubit in diameter to lay out the base as a number of revolutions, then made the height as an integral number of cubits, you unwittingly wind up with pi in the ratio.
Later, some wag pointed out that if one uses a measuring wheel one cubit in diameter to lay out the base as a number of revolutions, then made the height as an integral number of cubits, you unwittingly wind up with pi in the ratio.