Trigonometry · Medium problem

Surveying & height. Points $A$ and $B$ are $250$ m apart on level ground, and a tower stands at $T$ with $\angle TAB=68^\circ$ and $\angle TBA=54^\circ$. (a) Find the ground distances $TA$ and $TB$. (b) If the angle of elevation from $A$ to the top of the tower is $40^\circ$, find the tower's height.