Answer:
119
Step-by-step explanation:
By using exterior angle theorem, we know that 31+angle 1 =150. therefore angle 1=119. Exterior angle theorem is where an angle exterior of an angle in the triangle addus up to 180 degreees, we also know the angles in a triangle sum to 180 degrees. Both sides have a common angle. If we subract it from the equation, we get what is said above.
