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.

3. http://www.5min.com/Video/An- Introduction-to-Slope-160958776

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

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

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

7. http://www.5min.com/Video/Interpreting- Slope-from-a-Graph-160959058 http://www.5min.com/Video/Interpreting- Slope-from-a-Graph-160959058 http://www.5min.com/Video/Interpreting- Slope-from-a-Graph-160959058 http://www.5min.com/Video/Interpreting- Slope-from-a-Graph-160959058

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 + 2andy = 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!