.Find the unknown angles in each of the following figures and mention the property used

Answer/Step-by-step explanation:

a. Angle y is vertically opposite the angle that measures 80°. Vertically opposite angles are said to be equal to each other, therefore, y = 80°

x + y + 50° = 180° (sum of angles in a ∆)

x + 80° + 50° = 180 (substitution)

x + 130° = 180°

x = 180° - 130° (subtracting 130 from each side)

x = 50°

b. x + 50° = 120° (sum of the 2 opposite interior angles in a ∆ = the exterior angle of the ∆)

x = 120 - 50 (subtracting 50 from each side)

x = 70°

y + x + 50° = 180° (sum of angles in a ∆)

y + 70° + 50 = 180° (substitution)

y + 120° = 180°

y = 180 - 120 (subtracting 120 from each side)

y = 60°