Angle 1 and Angle 2 create a supplementary angle (180 degrees)
Angle 1 + Angle 2 = 180
180 - 78 - 55 = 47° (Angle 2)
180 - 47 = 133° (Angle 1)
Question 4:
If you add an exterior angle and adjacent interior angle, it will add up to be 180°. If we were to divide in half (180 / 2 = 90). A right angle is an angle that measures 90°. Thus, proves that we can work it out with two right triangles.