$\triangle{ABC}$ is an equilateral triangle.
$|AD|=6$.
$|BD|=10$.
$|CD|=8$.
What is $m\angle{CDA}$?
First thing comes to mind is Ceva theorem. I used its trigonometric form to reach somewhere. Also, i tried to reach the result with trigonometry by drawing perpendicular to sides from $D$, hoping to exploit Viviani's theorem somehow. These trigonometric attempts came, because i can't find a geometric way to prove that angle is $150^\circ$.
I prefer a geometric solution but all approaches are welcome, especially if it's more direct.