ABCD is a parallelogram with side AB = 10 cm. Its diagonals AC and BD are of length 12 cm and 16 cm respectively. Find the area of the parallelogram ABCD.

The area of a parallelogram is p cm² and its height is q cm. A second parallelogram has equal area but its base is r cm more than that of the first. Obtain an expression in terms of p, q and r for the height h of the second parallelogram.

The area of a rhombus is 98 cm². If one of its diagonal is 14 cm, what is the length of the other diagonal?

The perimeter of a rhombus is 45 cm. If its height is 8 cm, calculate its area.