Solve the following math problem step by step. The last line of your response should be of the form Answer: \boxed{$Answer} where $Answer is the answer to the problem.

<image>isosceles trapezoid TWYZ with $\angle Z \cong \angle Y, m \angle Z=30 x$, $\angle T \cong \angle W,$ and $m \angle T=20 x$, find Z