Parts of the Triangle
Vertices (points A, B, C)
Sides (lines AB, BC, CD)
Angles (∡A, ∡B, ∡C)
Altitude or Height - segment joining one of a vertex and perpendicular to its opposite side. (line segment AD)
Median - a segment joining one of the vertex to the midpoint of the opposite side. (line segment AE)
I hope it help. ☺