The area  of a circle is 616 sq cm, find its circumference?

The area of the base of a right circular cone is 400π and its height is 15 cm. The curved surface of the cone ( in cm²) is:

A cylindrical well of depth 21 m with internal radius of 13 m is dug up. The mud, so detained, is spread evenly to form a platform of dimension 52 × 13.2. What is the height of the platform?

A regular hexagon has a side of 4 cm. Find its area. (in sq. cm)

The perimeter of a rectangle and equilateral triangle is equal. One side of the rectangle is also equal to the side of the triangle. Find the ratio of the areas of the rectangle and triangle?

50 men took a dip in a water tank 40 m long and 20 m broad on a religious day. If the average displacement of water by a man is $$ {4 m^{3}}$$ , then the rise in the water level in the tank will be:

A rectangular grass plot 80 m × 60 m has two roads, each 10 m wide, running in the middle of it; one parallel to length and the other parallel to breadth. Find the cost of gravelling the roads at ₹ 2 per m². 

The lengths of the parallel sides of a trapezium are 51 cm and 21 cm, and that of each of the other two sides is 39 cm. what is the area ( in cm²) of the trapezium?