Prove that the circle drawn with any side of a rhombus as diameter, passes through the point of intersection of its diagonals.
Let ABCD be a rhombus in which diagonals intersect at point O and a circle is drawn is drawn taking side CD as diameter
Now,
∠COD = 900
(Since, diagonals of rhombus intersect at 900)
Hence,
∠AOB = ∠BOC = ∠COD = ∠DOA = 900
Hence, point O has to lie on the circle