When we look at angles on a straight line, we find an important rule: the total of the angles is always 180 degrees. This happens because straight lines connect angles to the space around them.
Key Points to Remember:
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Linear Pairs:
- Angles that are next to each other and share the same corner are called linear pairs.
- For example, if angle A is 60 degrees, then the angle next to it, angle B, must be 120 degrees because 60 + 120 = 180.
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Supplementary Angles:
- Angles on a straight line are also called supplementary angles.
- If angle C is 75 degrees, then angle D will be 105 degrees since 75 + 105 = 180.
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Real-Life Examples:
- Knowing about these angle rules is really important in jobs like building and engineering, where getting the angles right matters a lot.
- For example, when making things like traffic signs and road layouts, it's important that all angles add up to 180 degrees to keep everything safe and in line.
Patterns:
- No matter how you look at angles on a straight line, they always add up to 180 degrees. This is a basic rule in geometry.
- In fact, in nearly every case involving angles on a straight line, you can expect this rule to hold true, showing how common it is in geometry.