Become math lovers!

The altitude of a geometric figure is a line segment that shows the figure's height.

In order for the line segment to be an altitude, it must be perpendicular to the base of the figure. Otherwise, it cannot be called a height. The height of all geometric figures in this lesson is the red segment.

For the prism on the right, the height will change if you make the figure sit on the other base as illustrated below.

For a pyramid or cone, the height is the perpendicular line segment from the vertex to the base of the pyramid or the cone.