Image caption, The diameter is the whole distance across the circle, through its centre. The diameter is two radii. The radius is half of the diameter. The radius is the distance from the centre ...

Pi is part of Egyptian mythology Egyptians believed that the pyramids of Giza were like math marvels, built on the principles ...

Friday is Pi Day, a national celebration of the mathematical concept, which is the ratio of a circle's circumference to its diameter and equals 3.14 ... divides the circumference of a circle by its ...