geometry
posted by sally .
Trapezoid ABCD has height 4, BC=5, and AD and BC are perpendicular. Find the area of the trapezoid.

You are not using the conventional way to describe a polygon, which is, to list the vertices in either clockwise or counterclockwise order.
if AD is perpendicular to BC, one of the letters would have to be common to both segments.
I cannot visualize your figure.