Remote Interior and Exterior Angles in Triangles

Answer:
∠ 2 = 60°
Step-by-step explanation:
the exterior angle of a triangle is equal to the sum of the 2 remote interior angles.
123° is an exterior angle of the triangle , then
∠ 2 + 63° = 123° ( subtract 63° from both sides )
∠ 2 = 60°