Median of the trapezoid theorem

In elementary geometry, it is a theorem that the median of a trapezoid is equal in length to the average of the lengths of the two bases. Here, a trapezoid is a quadrilateral with two opposite sides parallel, and its median is defined as the line segment connecting the midpoints of the two non-parallel sides of the trapezoid. The median is parallel to the two parallel sides, and equidistant from them.
One application of the theorem is to simplify the statement of the area formula for a trapezoid. The area is the product of the median length and the height of the trapezoid (the distance between its two parallel sides).