In the figure above, MNOP is a parallelogram, diagonals MO and PN intersect at Q, `angle OPQ=40^(@) and angleOMN=30^(@)`. Find `angleOQN`.

PORS is a parallelogram whose diagonals intersect at M. If angleLPMS = 54^@, angleQSR=25^@ and angleSQR=30^@, find :

In cyclic quadrilateral ABCD. Diagonals AC and BD intersect at P. If angle DBC = 70^(@) and angle BAC = 30^(@) , find angle BCD.

In the given figure, ABCD is a cyclic quadrilateral where diagonals intersect at P such that angleDBC=40^(@) and angleBAC=60^(@) find (i) angleCAD (ii) angleBCD

The diagonals of a parallelogram ABCD intersect at O. If angleBOC=90^(@)andangleBDC=50^(@),"find"angleOAB.

In the adjoining figure, ABCD is a rectangle whose diagonals AC and BD intersect at O. If angle OAB =28^(@), " find " angle OBC.

In the figure above, ABCD is a parallelogram , and if AC=30 cm and BD=20 cm, find CP+DP.