1. Slopes
Objective: By the end of this unit students will be able to identify, interpret and calculate the slope of a line.

2. Slope
What is a slope? The rate at which a line increases or decreases Describe a positive slope/negative slope Pos line goes up from right to left Neg line goes down from right to left Describe a steep slope a narrow slope Steep line gets closer and closer to vertical Narrow line gets closer and closer to horizontal

3. Examples

4. Calculating Slope
What is slope? rise of a line over the run Change in y or change in x From a graph? Find two points on the graph Connect them using a triangle Find length of sides of the triangle Write as slope From a 2 points?

5. Examples
Calculate slope given the points (-2,3) and (5,7)

6. Vertical and Horizontal Lines
What is a vertical Line? Goes up and down with no left or right movement What is the slope of a vertical line? rise/run any # / 0 = undefined What is a horizontal line? Goes left and right with no up or down movement What is the slope of a horizontal line? rise over run 0/ any # = 0

7. Examples
Calculate the slope (3,5) and (3,10) (-2,4) and (5,4)

8. Parallel and Perpendicular Lines and Slopes
Parallel? Never touch Slopes are the same Perpendicular Intersect at 90 degrees Slopes are opposite reciprocals

9. Examples
If the slope of a line is 4/5 What is the slope of a line parallel?perpendicular? If the slope of a line is -3

10. Homework
Worksheets Why did the skeleton visit a butcher shop – interpreting graphs Slope of line – from graph, points, parallel and perpendicular