Show that the following points (3, 2), (3, 2), (1, 2) and (1, 2) taken in order are vertices of a square.
Let the points (3, –2), (3, 2), (–1, 2) and (–1, –2) be A, B, C and D respectively. By distance formulae AB=BC=CD=AD=4units and AC=BC and AC2=AB2+BC2 and BD2=CD2+AD2 and slope of BD = -1 x slope of AC. Therefore given points form a square