From a circle of radius a, a sector, which subtend an angle π/5 at the centre has been cut off. The perimeter of the remaining part of the circle is

If the areas of circular ring having inner and outer radius 8 cm and 12 cm respectively is equal to the total surface area of cylinder of radius R₁ and height h, then h in terms of R₁ will be :

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 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. 

A polygon has 14 sides then find out No. of diagonals in that polygon. 

A corner of a cube of side length 8 m. When cut by a plane which bisects the sides of the cube, we get a pyramid whose volume is : 

A polygon has 9 sides, what is its interior angle?

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