If the four corners of a rectangle with rational sides have rational distances , , , to a point , the resulting rectangle-point combination is sometimes called a rational rectangle. A given set of four distances to a point supports four distinct rectangles. The British flag theorem holds for distances to the opposing corners.[more]
Whether a square can be a rational rectangle is a long-unsolved problem.[less]
 Wikipedia. "British Flag Theorem." (Mar 17, 2022) en.wikipedia.org/wiki/British_flag_theorem.