Orthocenter

Measure the interior angles of the triangle. Make sure of all your measurements are between 0 and 180. Construct the altitude of the triangle. To complete this, click on a vertice and construct a line perpendicular to the opposite side of the vertex. The altitude is the same as a perpendicular bisector because it intersects the side at a 90 angle. How is the altitude different from an perpendicular bisector.

The altitude is the same as as an angle bisector and median because it goes from the vertex to the opposite side of the triangle. How is an altitude different from a median or angle bisector?

Continue to click and drag the triangle. Can the altitude of the triangle be outside the triangle? If so, what kind of triangle has the altitude outside the triangle?

Construct the other altitudes of the triangle. Use the intersect tool and label the point of concurrency of the altitudes. The point of concurrency of the altitudes is called the orthocenter. Where is the orthocenter if the triangle is acute?

Where is the orthocenter if the triangle is right?

Where is the orthocenter if the triangle is obtuse?