please answer in full sentences , and show your work.
![please answer in full sentences and show your work class=](https://us-static.z-dn.net/files/d42/b194a6055d951250eb15e7dafd897a2e.png)
Answer:
b) ∠4 = m∠U + m∠L
∠4 = 25° + 52°
∠4 = 77°
Step-by-step explanation:
a) Exterior Angle Theorem. The measure of an exterior angle of a triangle is equal to the sum of the measures of the two non-adjacent interior angles of the triangle.