# Orthocenter Exploration

Recall that 3 or more lines are said to be concurrent if and only if they intersect at exactly 1 point.

## Here, the triangle's 3 vertices are MOVEABLE. Slide the bottom slider really slowly and carefully observe what is taking place.

The point * O* you see is said to be the

**orthocenter**of the triangle. What do you notice? What do you wonder? Describe!

Is it possible for the **orthocenter** of a triangle to lie **INSIDE THE TRIANGLE?** If so, under what condition(s) do/does this occur?

Is it possible for the **orthocenter** of a triangle to lie **ON THE TRIANGLE ITSELF? ** If so, under what condition(s) do/does this occur?

Is it possible for the **orthocenter** of a triangle to lie **OUTSIDE THE TRIANGLE? ** If so, under what condition(s) do/does this occur?

Without Googling, how would you define the term **ORTHOCENTER OF A TRIANGLE? **Describe.