Pi is the circumference of a circle divided by its diameter which is = 3.14 radians which equals the degree measure of a line (180°)... So, Pi = 180° (the degree measure of a line)
Therefore, 2 Pi = 6.28 radians which equals 360° and is equivalent to the degree measure of a circle.
Pi = 180° (a line)
2 Pi = 360° (a circle)
and if pies are always circles (and they just are!), then 2 Pi = pie.
