In 1880, the German mathematician Ferdinand von Lindermann proved that pi is a transcendental number and that squaring a circle is impossible under the constraints of Euclidean geometry.

Time is a flat circle, Matthew McConaughey tells us, neglecting to explain how then we could measure time's circumference to derive its diameter, using pi. (Maybe it's best not to take the ...

During the first celebration, the Exploratorium's employees marched around one of the circular spaces of the museum because Pi is the ratio of a circle's circumference to its diameter.