1. The [b]orthocenter[/b] is the point where the[b] three altitudes[/b] of a triangle intersect.[br][br]2. In the applet, you’ll see an orange point labeled O, which is the [b]orthocenter[/b].[br][br]3. [b]Click and drag the triangle’s white vertices[/b] to create different triangle shapes.[br][br]4. [b]Slide the slider[/b] to activate the altitudes and the orthocenter.[br][br]5. Watch where the orthocenter moves as the triangle changes.[br][list][*]Is it inside, on, or outside the triangle?[br][/*][/list][br]6. Spend a few minutes exploring. Try acute, right, and obtuse triangles.[br][br]7. If you need help, scroll to the bottom and watch the [b]“Quick (Silent) Demo.”[/b]