There are so many lines that can be drawn through a triangle that give us some awesome properties to look at. In this activity, students will be looking at one of those sets of lines called altitudes. There are two different files, one for more advanced users without much description as far as construction and a docx file that shows much more construction detail for students.

This is a Java Applet created using GeoGebra from - it looks like you don't have Java installed, please go to

Nicholas F. Bennett, Created with GeoGebra