Jill Casey

You will be constructing 3 altitudes in one triangle.


1. Select the triangle tool and create an acute, scalene triangle. Make sure to select the pointer tool afterwards in order to not keep creating polygons! 2. Select the point and line tool (4th from left) and choose perpendicular line from the drop down menu. The directions on how to select the items in order to create a perpendicular line will appear at the bottom of the screen. (Select a point and the segment opposite that point.) 3. You will do this two more times to create three altitudes.

What do you notice about the three altitudes?

This point is special! This point of concurrency is called the ORTHOCENTER of the triangle.