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

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.

Introduction-to-Slope

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 =

∆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 =

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

Slope-from-a-Graph Slope-from-a-Graph Slope-from-a-Graph Slope-from-a-Graph

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

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

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

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

LET’S BUILD A STAIRCASE!