Constructing a Perpendicular Line

1. Construct a circle centered at point C that goes through point A. 2. Label the intersection points of the circle and the line as A and D. Construct the midpoint of segment AD. Connect the midpoint of segment AD to point C. This new line is perpendicular to line AB. 3. After you are done, drag points A, B, and C to verify that your construction will always produce a perpendicular line. 4. Use the angle measurement tool to verify that the lines are perpendicular. 5. Use the slope tool to find the slop of both lines. What observations can you make about the slopes of perpendicular lines?