noun
tau
A mathematical constant equal to twice pi.
A full turn measures tau radians.
Etymology
Tau borrows the Greek letter-name for a mathematical constant. The symbol designates a full-circle measure equal to twice pi.
More examples
- The teacher defines tau as two times pi.
- Using tau, the circumference equals tau times the radius.
- She writes the circle formula with tau instead of two pi.
Forms
tau · taus