Supplementary Angles (A) - Free Printable

Let's solve the problem step by step.

🔷 Problem: Identify the missing angle measurement in each set of supplementary angles.

> Supplementary angles are two angles that add up to 180°.
> If one angle is given, the other can be found using:
> $$
> \text{Missing angle} = 180^\circ - \text{Given angle}
> $$

We have 8 diagrams, each showing a straight line (DC) with a point A on it, and a ray AB forming an angle at point A. The angles shown are between the ray AB and either AD or AC (which are parts of the straight line). Since DC is a straight line, the angles at point A form a linear pair — meaning they are supplementary.

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Let’s go through each diagram:

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1. First Diagram

- Given angle: $94^\circ$
- Missing angle: $180^\circ - 94^\circ = 86^\circ$

✔ Answer: 86°

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2. Second Diagram

- Given angle: $43^\circ$
- Missing angle: $180^\circ - 43^\circ = 137^\circ$

✔ Answer: 137°

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3. Third Diagram

- Given angle: $65^\circ$
- Missing angle: $180^\circ - 65^\circ = 115^\circ$

✔ Answer: 115°

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4. Fourth Diagram

- Given angle: $40^\circ$
- Missing angle: $180^\circ - 40^\circ = 140^\circ$

✔ Answer: 140°

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5. Fifth Diagram

- Given angle: $79^\circ$
- Missing angle: $180^\circ - 79^\circ = 101^\circ$

✔ Answer: 101°

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6. Sixth Diagram

- Given angle: $158^\circ$
- Missing angle: $180^\circ - 158^\circ = 22^\circ$

✔ Answer: 22°

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7. Seventh Diagram

- Given angle: $90^\circ$
- Missing angle: $180^\circ - 90^\circ = 90^\circ$

✔ Answer: 90°

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8. Eighth Diagram

- Given angle: $129^\circ$
- Missing angle: $180^\circ - 129^\circ = 51^\circ$

✔ Answer: 51°

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✔ Final Answers:

| Diagram | Given Angle | Missing Angle |
|--------|-------------|----------------|
| 1 | 94° | 86° |
| 2 | 43° | 137° |
| 3 | 65° | 115° |
| 4 | 40° | 140° |
| 5 | 79° | 101° |
| 6 | 158° | 22° |
| 7 | 90° | 90° |
| 8 | 129° | 51° |

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📌 Summary:

All missing angles were found using the rule:
$$
\text{Supplementary angles sum to } 180^\circ
$$
So for any given angle $x$, the missing angle is $180^\circ - x$.

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