Angle Pairs Review Part 2

Take out your U1 Lesson 3 Notes

Make sure you have them completed. Click this link for the filled in slides.

https://docs.google.com/document/d/1bFIrodPsTDxKO0GhxWD7TMqWX7yi2FMgKmItfLqPVZg/edit​

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Add anything you learn as you work through these slides!​

​A transversal is a line that crosses at least two other lines.​

​Transversals

Draw

Sketch two lines in black. Then sketch a transversal in red.

Intersecting Lines

When 2 lines cross, 4 angles are formed that all have the same vertex.​

​When a transversal crosses 2 lines, it forms 2 groups of 4 angles.

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In this case, Angles 1, 2, 3, and 4 all have the red vertex. Angles 5, 6, 7, and 8 all have the blue vertex.​

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Intersecting Lines

In each group of 4, we can find adjacent angles and vertical angles.

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For example, Angle 1 and Angle 4 are vertical angles because they're across from each other.

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Angle 2 and Angle 4 are adjacent because they're next to each other. ​More specifically, they are a linear pair.

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Fill in the Blanks

Fill in the Blanks

Corresponding Angles

In each group of 4, we have 4 positions:

​Top left

Top right

Bottom left

Bottom right​

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Each red angle has a matching angle in the same position in the blue group.​ These pairs are called corresponding angles.

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Example. Angle 1 is the top left of the red group and Angle 5 is the top left of the blue group, so Angle 1 and Angle 5 are corresponding angles​

Multiple Choice

Which position is angle 7 in within the blue group of angles?

• Top left

• Top right

• Bottom left

• Bottom right

Fill in the Blanks

Interior vs Exterior

The angles between the two lines are called interior angles.

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The angles outside the two lines are called exterior angles.​

Draw

One of the exterior angles is marked. Circle the labels of the other exterior angles.

Draw

Circle the labels of all of the angles that are on the opposite side of the transversal from angle 1.

Consecutive vs Alternate

Consecutive angles are on the same side of the transversal.

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Alternate angles are on opposite sides of the transversal.​

Example: Angles 1 and 8 form an alternate pair.​

Putting it together

We have seen that angles 1 and 8 are both exterior (outside the lines) and they are alternate (opposite sides of the transversal).

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This means angles 1 and 8 are alternate exterior angles. ​

Multiple Choice

Angle 3 and Angle 6 are:

• Alternate interior angles

• Alternate exterior angles

• Consecutive interior angles

• Consecutive exterior angles

Summary

These are questions to ask to determine what type of angle pair you have.

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​*Do the two angles share a vertex?

*Are the two angles in the same position in the group of 4?

*Are the two angles on the same side of the transversal?

*Are the two angles ​between the two lines or outside the two lines?

Parallel Lines

Two lines are parallel if they never cross.​

Parallel Lines

Notice these two lines are NOT parallel.

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This is because if you extended them, eventually they would cross.​

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Parallel Lines and Transversals

When the lines crossed by a transversal are parallel, our angle pairs have special properties.

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​Alternate interior angles, alternate exterior angles, and corresponding angles are congruent. This means if you know the measure of one of the angles, its pair is the same.

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Multiple Choice

What type of angle pair are Angle 4 and Angle 5?

• Corresponding

• Alternate Interior

• Consecutive Exterior

• Alternate Exterior

Multiple Choice

Line l and line m are parallel. If Angle 4 measures $$120\degree$$ , then Angle 5 measures:

• $$120\degree$$  

• $$60\degree$$  

• $$180\degree$$  

• $$100\degree$$  

Parallel Lines and Transversals

When the lines crossed by a transversal are parallel, then consecutive interior angles and consecutive exterior angles are supplementary. This means they add to 180°.

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Multiple Choice

What type of angle pair are Angle 3 and Angle 5?

• Corresponding

• Consecutive Interior

• Consecutive Exterior

• Alternate Exterior

Multiple Choice

Line l and line m are parallel. If Angle 3 measures $$120\degree$$ , then Angle 5 measures:

• $$120\degree$$  

• $$60\degree$$  

• $$180\degree$$  

• $$100\degree$$  

​Next Steps

Retake the 1.2 and 1.3 Check-ins on Schoology.

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1.2: https://learn.rdale.org/course/6246149508/assessments/6320583464​

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1.3:

https://learn.rdale.org/course/6246149508/materials?f=640258236​

Poll

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