Diagonals of rhombus ABCD intersect each other at point O. Prove that :
`" "OA^(2)+OC^(2)=2AD^(2)-(BD^(2))/2`

ABCD is a trapezium such that AB||CD. Its diagonals AC and BC intersect each other at O. Prove that (AO)/(OC) = (BO)/(OD)

In a trapezium ABCD, side AB is parallel to side DC, and the diagonals AC and BD intersect each other at point P. Prove that : PA xx PD = PB xx PC .

The diagonals of a quadrilateral ABCD intersect each other at the point O such that (A O)/(B O)=(C O)/(D O) . Show that ABCD is a trapezium.

if diagonals of a parallelogram bisect each other,prove that its a rhombus

Prove that :The diagonals of a rhombus bisect each other at right angle.

ABCD is a trapezium in which AB||DC and its diagonals intersect each other at the point O. Show that (A O)/(B O)=(C O)/(D O) .

In a trapezium ABCD, side AB is parallel to side DC, and the diagonals AC and BD intersect each other at point P. Prove that : DeltaAPB is similar to DeltaCPD .

In figure , if Ababs()DC and AC, PQ interrest each other at the point 0. Prove that OA.CQ=OC.AP.

In the adjoining figure, ABCD is a quadrilateral in which AD ||BC . AC and BD intersect each other at point 'O'. Prove that: area of Delta COD = " area of " Delta ABO

In quadrilateral ABCD, the diagonals AC and BD intersect each other at point O. If AO = 2CO and BO = 2DO, show that: OA xx OD = OB xx OC .