Question

what is ab in the figure?
a median
none of the above
an altitude
a perpendicular bisector

Explanation:

A median of a triangle is a line - segment that joins a vertex to the mid - point of the opposite side. In the figure, the blue line segment \(AB\) joins a vertex of the triangle to the mid - point of the opposite side (as indicated by the equal marks on the opposite side segments). An altitude is a perpendicular line from a vertex to the opposite side. A perpendicular bisector bisects a side at a right - angle. Since the line segment \(AB\) joins a vertex to the mid - point of the opposite side, it is a median.

Answer:

A. a median