Identify linear pairs, vertical angles, complementary angles, and supplementary angles.

1. Pairs of Angles
Objectives:
The student will be able to (I can):
Identify
• linear pairs
• vertical angles
• complementary angles
• supplementary angles
and set up and solve equations.

2. adjacent
angles
linear pair
Two angles in the same plane with a
common vertex and a common side, but no
common interior points.
Example:
∠1 and ∠2 are adjacent angles.
Two adjacent angles whose noncommon
sides are opposite rays. (They form a line.)
Example:
1
2

3. vertical angles Two nonadjacent angles formed by two
intersecting lines. They are alwaysThey are alwaysThey are alwaysThey are always
congruent.congruent.congruent.congruent.
Example:
∠1 and ∠4 are vertical angles
∠2 and ∠3 are vertical angles
1
2
3
4

4. complementary
angles
supplementary
angles
Two angles whose measures have the sum
of 90º.
Two angles whose measures have the sum
of 180º.
∠A and ∠B are complementary. (55+35)
∠A and ∠C are supplementary. (55+125)
A
55º
B
35º
C
125º

5. Practice 1. What is m∠1?
2. What is m∠2?
3. What is m∠3?
1 60˚
51˚ 2
105˚
3

6. Practice 1. What is m∠1?
180 — 60 = 120˚
2. What is m∠2?
3. What is m∠3?
1 60˚
51˚ 2
105˚
3

7. Practice 1. What is m∠1?
180 — 60 = 120˚
2. What is m∠2?
90 — 51 = 39˚
3. What is m∠3?
1 60˚
51˚ 2
105˚
3

8. Practice 1. What is m∠1?
180 — 60 = 120˚
2. What is m∠2?
90 — 51 = 39˚
3. What is m∠3?
105˚
1 60˚
51˚ 2
105˚
3