Definition: When altitude is used in math, it's generally referring to the altitude of a polygon. For instance, in the altitude of a triangle, the altitude refers to the perpendicular distance from the vertex to the opposide. In the image, note that the altitude is AD. AD is the altitude from A to BC.
Examples:
Altitudes in math usually refer to height, however, it will always be the height that is perpindicular to the base. Some problems in geometry will require you to determine the measurement of the altitude based on knowing other measurements of the polygon.
