The Wallace-Simson line
Task
Construct the Wallace-Simson line and animate your construction.
Explore the construction and learn how to create the Wallace-Simson line with GeoGebra Geometry. Then try it yourself by following the instructions below.
Explore the construction...
Instructions
Note: If you're using the Mobile App make sure that the chosen Labeling option is New Points Only. You can change this by going to the Settings in the app's menu and then selecting General.
| 1. |  | Construct a triangle using the Line tool. The points A, B and C are intersection points of the lines. |
| 2. |  | Select the Circle through 3 Points tool and select the points A, B and C. |
| 3. |  | Create point D on the outline of the circle. |
| 4. |  | Activate the Perpendicular Line tool. Create three perpendicular lines through point D. The first line should be perpendicular to AB, second to BC and third to AC. |
| 5. |  | Select the Intersect tool and create the points E, F and G by clicking on a line (AB, BC and AC) and it's corresponding perpendicular line. |
| 6. | | Create a line through point E and G. Change the style of this line. |
| 7. | | Move point D. Note: When using the Online or Desktop App you can animate point D by selecting it and then choosing Animation. |