I. Move up to "Graph" on the menu bar and "Snap to Grid". This makes a coordinate graph. Under "Graph", pick "Plot Points". Use a line segment to connect the two points.

1. First, predict your slope using the rise/run.
2. Record your answer on paper.Sketch a picture of your points.
3. Select the segment.
4. Go to "Measure" and find "Slope". Click on slope.
5. Did you get what you predicted?
6. Record each of these points on your graph paper and show your lines. Find the slope of each line. Record results on the graph paper.
1. Graph points (3,4) and (-1,-4)
2. Graph points (2,5) and (0,3)
3. Graph points (-3,1) and (-1,-3)

II. Start a new sketch and pick two points. Connect the points and find the slope. Make another line parallel to the first. Check the slope. Is it the same? Sketch your results on the graph paper. What problems, if any, did you encounter? Write your reactions on your paper.

III. Begin a new sketch. Construct 2 lines (label them AB and CD).Have them intersect at point E. Measure the slopes of the lines. Draw a picture of your lines on graph paper and label the slopes.

1. Drag point C around so that the lines that cross are going in opposite directions. Draw a picture of your lines and label the slopes. Open Geometer's Sketchpad.

   III. Begin a new sketch. Construct 2 lines (label them AB and CD).Have them intersect at point E. Measure the slopes of the lines. Draw a picture of your lines on graph paper and label the slopes.

2. Drag point C to make a line parallel to line AB. Draw a picture of your parallel lines. Find the slope of each line. What do you observe about the slopes?

3. Drag point C to make a line perpendicular to line AB. Draw a picture of your perpendicular lines. Find the slope of each line. What do you observe about the slopes?

4. Drag point C to make a vertical line to line AB. Draw a picture of your lines. Find the slope of each line. What do you observe about the slopes?

5. Drag point C to make a horizontal line to line AB. Draw a picture of your lines. Find the slope of each line. What do you observe about the slopes?

6. What happens to the slopes of lines that rise going from left to right?

7. What happens to the slopes of lines that fall going from left to right?

8. What do you see ? Write a short reaction to what you observed.