Cotangent of Three Right Angles

Theorem

 * $\cot 270^\circ = \cot \dfrac {3 \pi} 2 = 0$

where $\cot$ denotes cotangent.

Also see

 * Sine of Three Right Angles
 * Cosine of Three Right Angles
 * Tangent of Three Right Angles
 * Secant of Three Right Angles
 * Cosecant of Three Right Angles