1. Angle Relationships

2. 90 and 180 degree angles……
90 degree angle:
180 degree angle:

3. Types of angles…… Acute – angles less than 90 degrees.
Right – angles with exactly 90 degrees.

4. Obtuse – angles greater than 90 degrees but less than 180 degrees.
Straight – angles that are 180 degrees and form a line.

5. Identify these angles…..B. C. D.
A. Obtuse
B. Right
C. Acute
D. Straight

6. Adjacent Angles……
Two angles that share a common side are adjacent angles.
Example:

7. Non-adjacent Angles……
Angles that do not share a common side are non-adjacent angles.
Example:

8. Supplementary
Two angles whose sum is 180.

9. Complementary
Two angles whose sum is 90.

10. Perpendicular
If 2 segments are perpendicular to each other, then they form a 90 degree angle.
The symbol for perpendicular is an upside down T.
Example:

11. Let’s finish this problem...Remember that

12. Find x, given that

13. Vertical Angles……
Vertical Angles are two non-adjacent angles formed by intersecting lines.
Vertical Angles are congruent. (Equal)

14. Example……
Find the value of x.

15. Example…..
Find the

16. Linear Pairs
Linear Pair – a pair of adjacent angles whose non-common sides form opposite rays. 1 2
∠1 and ∠2 form a linear pair.

17. A linear pair is supplementary – the angle measures
add up to 180 degrees.
Find x:

18. Homework
Angle Relationships Worksheet