Morley's Trisector Theorem

Theorem
Let $\triangle ABC$ be a triangle.

Let the internal angles of $\triangle ABC$ be trisected.

Let the points where these angle trisectors first intersect be $D$, $E$ and $F$.


 * Morleys-Theorem.png

Then $\triangle EDF$ is equilateral.

Also known as
Morley's Trisector Theorem is also known just as Morley's Theorem.