The anwser is 12 hope it helps you
ST = 2TW since W is the midpoint of ST. So:-
8x + 10 = 2(6x - 7)
8x + 10 = 12x - 14
24 = 4x
x = 6
Therefore SW = ST = 58 and TW = 29
Since line AB and line CD are parallel, and line EF is perpendicular to line CD, line EF is also perpendicular to line AB.
Answer:
Line AB and line EF are perpendicular.
Hope this helps!