A median of a triangle is a line segment that connects a vertex to the midpoint of the opposite side of the vertex. The figure shows that from the vertex the lines go to the middle of the opposite side. You know that it is the midpoint because based on the figure, the two sides of the base are equally divided by the line. (Those markers on it, indicate that they are congruent).
A triangle has 3 medians, all coming from each corner of the triangle.
