Angle T and Angle R are vertical angles, which means they are congruent (equal in measurement)
Use substitution to go from
Angle T = Angle R
to
3x+36 = 6x-9
Now let's solve for x
3x+36 = 6x-9
3x+36-3x = 6x-9-3x
36 = 3x-9
36+9 = 3x-9+9
45 = 3x
3x = 45
3x/3 = 45/3
x = 15
Since x = 15, we can say,
Angle T = 3x+36
Angle T = 3*x+36
Angle T = 3*15+36 ... x is replaced with 15 (since x = 15; found above)
Angle T = 45+36
Angle T = 81
The final answer is 81 degrees