The area of a rhombus whose diagonals are of lengths 10 cm and 8.2 cm is:

A square and a rectangle have the same perimeter. Calculate the area of the rectangle if the side of the square is 60 cm and the length of the rectangle is 80 cm.

The area of a rhombus is 16 cm² and the length of one of its diagonal is 4 cm. Calculate the length of other diagonal.

The parallel sides of a trapezium measure 12 cm and 20 cm. Calculate its area if the distance between the parallel lines is 15 cm (in cm²).

From a circular sheet of radius 4 cm, a circle of radius 3 cm is cut out. Calculate the area of the remaining sheet after the smaller circle is removed.

A cuboidal box of dimensions 1 m × 2 m × 1.5 m is to be painted except its bottom. Calculate how much area of the box has to be painted (in m²).

In a trapezium, the parallel sides measure 40 cm and 20 cm. Calculate the area of the trapezium if its non-parallel sides are equal having the lengths of 26 cm (in cm²).

A diagonal of a quadrilateral is 30cm in length and the lengths of perpendiculars to it from the opposite vertices are 6.8cm and 9.6cm. Find the area of the quadrilateral (in cm²).

When a polygon ABCDE is divided into parts, as shown below. Find its area if AD = 8 cm, AH = 6 cm, AG = 4 cm, AF = 3 cm and perpendiculars BF = 2 cm, CH = 3 cm, EG = 2.5 cm (in cm²).