BCDE is a parallelogram. O is a point inside BCDE. OB, OC, OD and OE are joined. Prove that triangle BOC + triangle EOD = triangle EOB + triangle DOC.

If AB and CD are intersecting at ‘O’, OA = OB and OD = OC. Show that triangle AOD ~= triangle BOC

O is any point on the diagonal B D of the parallelogram A B C D . Prove that a r( triangle O A B)=a r(triangle O B C)

In the given figure, AB||CD and AB=CD , prove that: triangle AOB is congruent to triangle DOC.

ABCD is a parallelogram whose area is 100 sq.cm. P is any point inside the parallelogram (see fig.) find the area of triangle APB +triangle CPD .

O is any point inside a rectangle. Prove that OA^2+OC^2=OB^2+OD^2 .

O is any point inside a rectangle ABCD. Prove that OB^2+OD^2=OA^2+OC^2 .

In parallelogram ABCD, P is a point on side AB and Q is a point on side BC, prove that (i) Delta CPD and Delta AQD are equal in area. (ii) area (Delta AQD) = " area of " Delta APD + " area of " Delta CPB