A circle circumscribes a rectangle with sides 16 cm and 12 cm. What is the area of the circle?

Each side of a square is 12 cm long. The perimeter of this square is equal to the perimeter of a rectangle whose length is 16 cm. What will be the area of this rectangle?

The volume of a cuboid is 2 times the volume of a cube. If the dimensions of the side are 9 cm by 8 cm and 6 cm, then the total surface area of the cube is

The area of two equilateral triangles are in the ratio 25 : 36. Their altitudes will be in the ratio : 

The diagonal of a square is $${4\sqrt { 2}\ }$$ cm. The diagonal of another square whose area is double that of the first square is :

△ABC ∼ △DEF. If the areas of △ABC and △DEF are 100 cm² and 81 cm², respectively and the altitude of △DEF is 6.3 cm, then the corresponding altitude of △ABC is:

A prism with a right triangular base is 25 cm high. If the shorter sides of the triangle are in the ratio of 1 : 2 and the volume of the prism is 100 cm³ , what is the length of the longest side of the triangle?

The number of coins of radius 0.75 cm and thickness 0.2cm required to be melted to make a right circular cylinder of height 8 cm and base radius 3 cm is: