Constructing the Orthocenter of a Triangle

Open a new Geometry window.

Use the triangle construction tool to build a triangle.

Click on the three different parts of the screen to define the corners of the triangle.

Press Enter at each point.

Use the perpendicular line tool to construct the altitudes for each side.

Move to each side of the triangle and press Enter.

Then move to the opposite vertex so that the pointer hovers over the point.

Press Enter.

The altitudes meet at a point called the orthocenter.

Changing the shape of the triangle moves the orthocenter to a different part of the screen.