Supplementary Angles (A) - Free Printable

Let's solve the problem step by step.

🔷 Understanding Supplementary Angles

Supplementary angles are two angles that add up to 180 degrees. In each diagram, we have a straight line (D–A–C), and a ray from point A going upward to point B, forming two angles at point A. These two angles together form a straight angle, so:

> Angle DAB + Angle BAC = 180°

We are given one angle in each case and need to find the missing angle.

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🔷 Solving Each Diagram

#### 1. First Diagram
- Given: ∠DAB = 94°
- Find: ∠BAC

$$
∠BAC = 180° - 94° = 86°
$$

✔ Answer: 86°

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#### 2. Second Diagram
- Given: ∠BAC = 43°
- Find: ∠DAB

$$
∠DAB = 180° - 43° = 137°
$$

✔ Answer: 137°

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#### 3. Third Diagram
- Given: ∠DAB = 65°
- Find: ∠BAC

$$
∠BAC = 180° - 65° = 115°
$$

✔ Answer: 115°

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#### 4. Fourth Diagram
- Given: ∠DAB = 40°
- Find: ∠BAC

$$
∠BAC = 180° - 40° = 140°
$$

✔ Answer: 140°

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#### 5. Fifth Diagram
- Given: ∠DAB = 79°
- Find: ∠BAC

$$
∠BAC = 180° - 79° = 101°
$$

✔ Answer: 101°

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#### 6. Sixth Diagram
- Given: ∠DAB = 158°
- Find: ∠BAC

$$
∠BAC = 180° - 158° = 22°
$$

✔ Answer: 22°

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#### 7. Seventh Diagram
- Given: ∠BAC = 90°
- Find: ∠DAB

$$
∠DAB = 180° - 90° = 90°
$$

✔ Answer: 90°

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#### 8. Eighth Diagram
- Given: ∠BAC = 129°
- Find: ∠DAB

$$
∠DAB = 180° - 129° = 51°
$$

✔ Answer: 51°

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✔ Final Answers:

1. 86°
2. 137°
3. 115°
4. 140°
5. 101°
6. 22°
7. 90°
8. 51°

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📝 Summary

All answers were found using the supplementary angle rule:
> Missing angle = 180° − given angle

Each pair of angles forms a straight line, so their sum must be 180°.

Let me know if you'd like this formatted as a printable answer sheet!