Altitude of a Triangle Definition
The altitude or height of a triangle is the distance between a vertex of a triangle and the opposite side. It is the shortest line segment between a vertex of a triangle and the (possibly extended) opposite side. Altitude can also be used to refer to the specific length of this segment. Notably, the three altitudes of a triangle are concurrent, intersecting at the orthocenter. The altitude of a triangle is illustrated in the diagram below.
“Altitude of a Triangle.” Mathwords, www.mathwords.com/a/altitude_triangle.htm.