Answer:
The answer to your question is ∠1 = 40°
Step-by-step explanation:
Process
1.- Remember that the sum of supplementary angles equals 180°.
40° + x° + 90° = 180°
x° = 180° - 40° - 90°
x° = 180° - 130°
x° = 50°
2.- ∠x and ∠y are verticals so they measure the same.
3.- The sum of the internal angles in a triangle equals 180°.
90° + y° + ∠1 = 180°
90° + 50° + ∠1 = 180°
∠ 1 = 180° - 90° - 50°
∠ 1 = 180° - 140°
∠ 1 = 40°
