DISCOVER PERPENDICULAR
Instructions
Step 1. Construct
One the GeoGebra page you will see four geometric objects:
1. Point A
2. Point B
3. Point C
4. Line BC
On the Tool Bar there is a PERPENDICULAR LINE tool 
.Click on the PERPENDICULAR LINE tool to select it. Notice the instructions for this GeoGebra tool: Click first on Point A and then click on Line BC. This will create a new, perpendicular line. But just what is a “perpendicular line?”
Step 2. Experiment
Use the MOVE tool 
to experiment by moving Points A, B, or C. Move the two lines as well. Make observations. If needed, use the ZOOM IN 
or ZOOM OUT tool 
to change your view.
Step 3. New Construction
Use the DELETE OBJECT tool 
to click on all the points and lines on the GeoGebra page and delete them. Now use the NEW POINT tool 
, the LINE THROUGH TWO POINTS tool 
, and the PERPENDICULAR LINE tool to create your own perpendicular lines and again experiment by moving points or lines.
Step 4. Conclusions
So just what is a perpendicular line? Share your conclusions with your teacher.
.Click on the PERPENDICULAR LINE tool to select it. Notice the instructions for this GeoGebra tool: Click first on Point A and then click on Line BC. This will create a new, perpendicular line. But just what is a “perpendicular line?”
Step 2. Experiment
Use the MOVE tool to experiment by moving Points A, B, or C. Move the two lines as well. Make observations. If needed, use the ZOOM IN or ZOOM OUT tool to change your view.
Step 3. New Construction
Use the DELETE OBJECT tool to click on all the points and lines on the GeoGebra page and delete them. Now use the NEW POINT tool , the LINE THROUGH TWO POINTS tool , and the PERPENDICULAR LINE tool to create your own perpendicular lines and again experiment by moving points or lines.
Step 4. Conclusions
So just what is a perpendicular line? Share your conclusions with your teacher.