1. 2-23. One way to think about slope triangles is as stair steps on a line. (All writing on resource pg)
Picture yourself climbing (or descending) the stairs from left to right on each of the lines on the graph (below, right).  Of lines A, B, and C, which is the steepest?  Which is the least steep? 
Examine line D.  What direction is it slanting from left to right?  What number should be used for Δy to represent this direction?  
Label the sides of a slope triangle on each line.  Then determine the slope of each line.  
B is the steepest; C is the least steep.
Downward;  Δy is −2

2. 2.1.3 Slope
September 12, 2019
HW: 2-30 through 2-34

3. Objectives
CO: SWBAT use slope triangles both to compare the relative steepness of lines and for positive, negative, and zero slopes.
LO: SWBAT discuss with their teammates about slope.

4. 2-23. continued (All writing on resource pg)
How does the slope relate to the steepness of the graph? 
Cora answered part (d) with the statement, “The steeper the line, the greater the slope.”  Do you agree?  If so, use lines A through D to support her statement.  If not, change her statement to make it correct.
The value of slope indicates how steep the graph is.  The greater the slope, the steeper the line.  If the slope is positive, the line slants upward from left to right, while a negative slope indicates that the line slants downward.
In this case, she is correct.  The steepest line (B) has the largest value for slope (3).

5. 2-24. A is the steepest; B is steeper than C.
2-24. 
Which is the steepest line?  Which is steeper, line B or line C? 
Draw slope triangles for lines A, B, C, D, and E using the highlighted points on each line.  Label Δx and Δy for each.
Match each line with its slope using the list below.  Note: There are more slopes than lines. (on resource page)
Viewed left to right, in what direction would a line with slope − 3 5  point? How do you know?
Viewed left to right, in what direction would a line with slope  − 5 3  point?  How do you know?  How would it be different from the line in part (d)? 
A is the steepest; B is steeper than C.
It would slant downward from left to right because its slope is negative. A B D
It would slant downward from left to right because its slope is negative.  It would be steeper. C E

6. Hot Potato ∆𝑦 ∆𝑥 =− 1 2 ∆𝑦 ∆𝑥 =− 2 1 =−2 ∆𝑦 ∆𝑥 = 2 3 ∆𝑦 ∆𝑥 =0
2-25. Examine lines A, B, C, and D on the graph at right.  For each line, decide if the slope is positive, negative, or zero.  Then draw and label slope triangles on your resource page and calculate the slope of each line. (ALL ON RESOURCE PAGE)
∆𝑦 ∆𝑥 =− 1 2
∆𝑦 ∆𝑥 =− 2 1 =−2
∆𝑦 ∆𝑥 = 2 3
∆𝑦 ∆𝑥 =0
Hot Potato

7. A line that goes up 3 each time it goes over 5.
 2-26. On the resource page, graph a line to match each description below.
A line that goes up 3 each time it goes over 5.
A line with Δy = Δx.
A line with Δx = 4 and Δy = −6.
A line that has Δy = 3 and Δx = 0.