3.4 Slope

HW pg. 175 #3­9 odd, 13­29 odd 1

September 26, 2012

Oct 5­4:02 PM

BELLWORK1. Find the value of x that make p // q.

2. Which lines are parallel? 

(2x + 43) (3x)

#1

95

85

80

100

E

D

F

G

3. Can you prove a // b?

4. If so, what theorem would you use?

5. Are you ready for the 3.1­3.3 Quiz on Thursday?

p

q

a

b

#3­4

x = 43

EF // DG

yes

Alt. Interior < Converse

I hope so!

3.4 Slope

HW pg. 175 #3­9 odd, 13­29 odd 2

September 26, 2012

Oct 5­4:19 PM

3.4 Find and Use Slopes of LinesSlope: ratio of vertical change (rise) to horizontal change (run) between any 2 points.

Slope = rise change in y y 2 - y1 run change in x x 2 - x1

Negative Slope: falls from left to right

Positive Slope: rises from left to right

Zero Slope: horizontal line

Undefined Slope: vertical line

==run (x2 - x1)

rise (y2 - y1)

3.4 Slope

HW pg. 175 #3­9 odd, 13­29 odd 3

September 26, 2012

Oct 5­4:31 PM

Comparing Slopes: When 2 lines intersect, the steeper line has the slope with greater absolute value.

Postulate 17: Slopes of Parallel Lines 2 lines are // iff they have the same slope.m1 = m2

Postulate 18: Slopes of Perpendicular Lines 2 lines are iff the product of their slopes is -1.m1 * m2 = -1

3.4 Slope

HW pg. 175 #3­9 odd, 13­29 odd 4

September 26, 2012

Oct 6­11:50 AM

With your group, complete #3 in guided practice.

3.4 Slope

HW pg. 175 #3­9 odd, 13­29 odd 5

September 26, 2012

Oct 6­11:48 AM

3.4 Slope

HW pg. 175 #3­9 odd, 13­29 odd 6

September 26, 2012

Oct 6­11:54 AM

3.4 Slope

HW pg. 175 #3­9 odd, 13­29 odd 7

September 26, 2012

Oct 6­12:23 PM

With your group, complete problems 4 & 5 in guided practice.

3.4 Slope

HW pg. 175 #3­9 odd, 13­29 odd 8

September 26, 2012

Oct 6­1:19 PM

HW pg. 175 #3-9 odd, 13-29 odd