vertical angles are congruent
So the equation will be:
7t +1 = 8t -8 combine like terms
-8t. -8t
-t +1 = -8. Combine like terms
-1. -1
-t = -9 therefore t=9 now plug in 9 for t in the equation
7(9) + 1 = 8(9) - 8 and so on. Both angles should equal the same degree.
I hope this helps