Answer. Segment joining a vertex to the mid-point of opposite side is called a median. Perpendicular from a vertex to opposite side is called altitude. A Line which passes through the mid-point of a segment and is perpendicular on the segment is called the perpendicular bisector of the segment.
Hopefully this sounds smart...<span>If the drawing of your octagon (or whatever) has been separated into triangles, and one triangle's </span>area<span> is labeled, then you do not need to know the apothem. Just take the </span>area<span> of that one triangle, and multiply by the number of sides in the original</span>polygon<span>.</span>