Answer:
75°
Explanation:
The two given angle measures (defined in terms of x) are alternate interior angles. Therefore, the are congruent. This means that their angles measures are equal. We can express this with an equation, and solve for x:

↓ subtracting
from both sides

↓ subtracting 3 from both sides

Now, we can plug this into the bolded angle's definition:

↓ plugging in


↓ executing the multiplication

↓ executing the addition
