A parallelogram ABCD with its diagonals meeting at the point O is shown in the diagram . AB is extendedto P such that BP=AB . THe line that passes through D and is parallel to AC meets PC produced at point R and angle CRD =90 .
(1) SHow that the triangles ABD and BPC are congruent .
I managed to prove this .
(2) Show that ABCD is a rhombus .
Not sure bout (2) and (3)