1. WARM UP 1. Name the alternate interior angles
2. Name the alternate exterior angles
3. Name the corresponding angles

2. 4.6 Slope Obj: Understand concept of slope.
Relate slope of a line to its orientation in the coordinate plane
Recognize the relationships between slopes of parallel and perpendicular lines.

4. Change of y over the change of x Use m for slope Equation:1 2
m = 2 1

5. ∆y ∆x
m =
∆ Delta y over delta x
∆ delta means change
Rise over run

6. Find the slope of a line given two points?
(5, -2) (6, 3)

8. Four special slopes:
Positive slope: m>0
Negative slope: m<0

9. Horizontal slope: m=0
Slope is zero
Vertical slope: no slope undefined

10. Slope of parallel lines:
Parallel lines have the same slope but different y-intercepts
Graph: y = 2x + 2 and y = 2x - 3 on the same graph.

11. Perpendicular lines: slopes are the opposite reciprocals of each other
Their product equals -1.
Graph: y = x+3 and y = x -1 on the same graph.
= -1 

12. LET’S BUILD A STAIRCASE!