A pyramid has an equilateral triangle as its base, of which each side is 8 cm. Its slant edge is 24 cm. The whole surface area of the pyramid (in cm²) is:

What is the volume of the largest sphere that can be carved out of a wooden cube of side 21 cm?$$( π{22\over 7})$$

A circle touches all four sides of a quadrilateral ABCD. If AB = 18 cm, BC = 21 cm and  = 15 cm, then length CD is: 

A,B, C are three points such that AB = 9 cm, BC = 11 cm and AC = 20 cm. The number of circles passing through points A,B,C 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:

The perimeter of a semi-circle is 25.7 cm. What is its diameter (in cm)? (π = 3.14)

If the areas of two isosceles triangles are in the ratio of X² : Y², then the ratio of their corresponding heights is:

A conical vessel, whose internal radius is 20 cm and height is 27 cm, is full of water. If this water is poured into a cylindrical vessel with internal radius 15cm, what will be the height to which the water rises in it?