1. Angle Relationships
OBJ: To ID and use adjacent, vertical, complementary, supplementary, and linear pairs of angles, and perpendicular lines
To determine what info can and cannot be assumed in a picture

2. Angle Relationships Adjacent angles-V Y Z X W
Adjacent angles-
Angles with a common ray and vertex, but have no common interior pts
Vertical angles-
2 non-adjacent angles formed by 2 intersecting lines
Vertical Angles are congruent

3. Angle Relationships ContinuedV Y Z X W
Linear pairs:
Adjacent angles whose non-common sides are opposite rays
Supplementary angles-
2 angles whose sum is 180 degrees

4. Angle Relationships continued
Perpendicular lines- Lines that intersect to form a 90 degree angle
Complementary angles-
2 angles whose sum is 90 degrees

5. Example: Find x and 9x – 4 + 4x – 11 = 180 13x – 15 = 180 13x = 195G K H J I
9x - 4
4x - 11
Find x and
9x – 4 + 4x – 11 = 180
13x – 15 = 180
13x = 195
X = 15
9 ( 15 ) – 4 = ?
135 – 4 = 131

6. Your Turn: Find x and 13x + 7 = 16x - 20 27 = 3x 13 ( 9 ) + 7 = 124E A B C D
16x - 20
13x + 7
Find x and
13x + 7 = 16x - 20
27 = 3x
13 ( 9 ) + 7 = 124
9 = x
= 56

7. Example
The measure of the supplement of an angle is 60 less than 3 times the measure of the complement of the angle. Find the measure of the angle.
Let x = angle
The measure of the supplement is less than 3 times the complement
180 – x
3 ( 90 – x ) – 60 =
180 – x = 270 – 3x -60
2x = 30
x = 210
x = 15

8. Your Turn:
The measure of the complement of an angle is 3.5 times smaller than the measure of the supplement angle. Find the measure of the angle.
3.5 ( 90 – x ) = x
Solve for x.
X = 54

9. What Can Be Assumed? Open your book to page 38.
Read through the chart.
Let’s discuss anything you do not understand

10. Homework
Put this in your agenda
Pg odd