The area of a trapezium is 21 sq cm, the distance between the parallel sides is 3 cm and one of the parallel sides is 8.3 cm. What is the length of the other parallel side?
Identical cubes of largest possible size are cut from a solid cuboid of size 65 cm × 26 cm × 3.9 cm. What is the total surface area (in cm2) of all the small cubes taken together?