if one of the interior angles of a regular polygon is $$15\over 16$$ times of one of the interior angles of a regular decagon, then the number of diagonal of the polygon is.

What is the volume of a cylinder if the radius of the cylinder is 10 cm and height is 20 cm? (Take π = 3.14)

A prism and a pyramid have the same base and the same height. Find the ratio of the volumes of the prism and the pyramid.

A hemispherical bowl of internal radius 18 cm is full of liquid. This liquid is to be filled in cylindrical bottles each of radius 3 cm and height 6 cm. How many bottles are required to empty the bowl

What is the total surface area of a pyramid whose base is a square with side 8 cm and height of the pyramid is 3 cm? 

The difference between the length of two parallel sides of a trapezium is 12 cm. The perpendicular distance between these two parallel sides is 60 cm. If the area of the trapezium is 1380 cm², then find the length of each of the parallel sides (in cm).

Find the number of diagonals of a regular polygon, sum of whose interior angles is 2700⁰.

What is the perimeter of a square inscribed in a circle of radius 5 cm?