Let $P$ be a polygon.
In the words of Euclid:
In the above diagram, $Q$ is the apex.
In the above diagram, $ABCDE$ is the base of the pyramid $ABCDEQ$.
In the above diagram, $h$ is the height.
- Results about pyramids can be found here.
The word pyramid derives directly from the Classical Greek πυραμίς (pyramis) whose derivation is unknown.