1. Point A is the y-intercept of the line. You can adjust Point B to change the slope of the graph.[br]2. Create a new point that’s not on the graph. Create a line parallel to the red line that goes through this point.[br]3. Find the slope of both lines and write them on a piece of paper.[br]4. Push the refresh button in the upper-right corner of the coordinate grid. Change the slope and the y-intercept of the red line.[br]5. Create another point that is not on the line. Draw a line that is parallel to the red line and goes through this point. Write down the slope for both lines.[br]6. What do you notice about the slopes of parallel lines? Refresh the grid and try your prediction on a new line. Did it work?

7. Refresh the grid. Create a new point that is not on the line. Then, draw a line that goes through this point that is perpendicular to the line. [br]8. Write both slopes on a piece of paper.[br]9. Complete steps 7 and 8 again.[br]10. What do you notice about the slopes of perpendicular lines? Refresh the grid and try your prediction on a new line. Did it work?