Post on 31-Dec-2015
WARM UP
RATIOS Convert the units. (Lesson 3.8)
1. 5 days to hours
2. 36 inches to feet
3. 12 years to months
3
WARM UP
RATIOS Convert the units. (Lesson 3.8)
1. 5 days to hours
2. 36 inches to feet
3. 12 years to months
2
WARM UP
RATIOS Convert the units. (Lesson 3.8)
1. 5 days to hours
2. 36 inches to feet
3. 12 years to months
1
RATIOS Convert the units. (Lesson 3.8)
1. 5 days to hours
2. 36 inches to feet
3. 12 years to months
WARM UP 0
5.6 Perpendicular Lines
PERPENDICULARQUESTION: What is the definition of this word?
Lines that intersect at a RIGHT, or 90⁰, angle are called perpendicular.
90⁰ angle
5.6 Perpendicular Lines
EXPLORE1. This line has a slope
of . Copy the line onto a piece of graph paper.
m = 3
4
5.6 Perpendicular Lines
EXPLORE2. Draw a line on the graph paper that is perpendicular to the first line.
5.6 Perpendicular Lines
In a coordinate plane, two nonvertical lines are perpendicular if and only if the product of their slopes is -1.
y = x
y = -2x + 3
• -2 = -1
5.6 Perpendicular Lines
EXAMPLE 1 IDENTIFY PERPENDICULAR LINESDetermine whether the lines are perpendicular.SOLUTIONThe lines have slopes of and -3. Because • -3 = -1, The lines are perpendicular.
y = x -1
y = -3x + 4
5.6 Perpendicular Lines
CHECK POINT
Graph and determine whether the lines are perpendicular.1. y = 3x + 2, y = -3x -1
2. y = x + 1, y = - x + 1
#1: NOT PERPENDICULAR!#2: PERPENDICULAR!
CERTIFIED