1. Slope of a Line Slope basically describes the steepness of a line.

2. I IV III II You should already be familiar with the coordinate grid, specifically the x and y axis, and the 4 quadrants. The x axis represents a horizontal (left or right) move. The y axis represents a vertical (up or down) move.

3. If a line goes up from left to right, then the slope has to be positive. If a line goes down from left to right, then the slope has to be negative.

4. Horizontal lines have a slope of zero. Vertical lines have no slope. Horizontal Vertical m = 0 m = no slope

6. The word slope is used to describe the measurement of the steepness of a straight line. The higher the slope, the steeper the line. The slope of a line is a rate of change.

7. Slope is a ratio and can be expressed as: change in y over change in x. or or or

8. Definitions of Slope Slope is simply the change in the vertical distance over the change in the horizontal distance.

9. For every one unit that is moved on the x-axis, two units are moved on the y-axis. This is true at any location on the line. So the slope is 2/1. XY -4-7 -3-5 13 25

10. The formula above is the one which we will use to find the slope of specific lines. In order to use that formula we need to know, or be able to find 2 points on the line.

11. Example So, slope is 1/3

13. Graph the following and determine the rate of change (slope). Mary is cutting grass. After 15 minutes, she has cut 25 ft 2. After an hour, she has cut 100 ft 2. What is the slope of the line? ft 2 100 90 80 70 60 50 40 30 20 10 0 1530456075 minutes (15,25) (60,100) 100-25 = 60-15 75 = 15 = 5 45 9 3

14. The building code for using asphalt shingles on roofs states that the minimum pitch must be a rise of 4" for every 12" of horizontal distance (run) covered. Asphalt shingles are not to be used on roofs that have very little steepness. Builders check to see what the pitch (slope) of the roof is before using asphalt shingles.

15. A = (2, 4) B = (-3, -2) C = (5, 4) D = (-3, 7) E = (-2, 6) F = (6, -8) A C D F E B Line AB = 6/5 Line BE = 8 Line BC = 3/4 Line AE = -1/2 Line CD = -3/8 Line CE = -2/7 Line DE = -1 Line AC = 0 Line EF = -7/4 Line AD = -3/5 Line AF = -3 Line BD = none AB BE BC AE CD CE DE AC EF AD AF BD Find the slope of line…