Volume of Cylinders:

Right Circular Cylinder:
            A cylinder whose base is a circle is called circular cylinder. If the axis of the cylinder is perpendicular to its base then cylinder is called right circular cylinder.

            If  is the radius of the circular base,  is height,  is lateral surface area,  is volume and  is perimeter of the base, then

             
            i.e         (i)                           ( being radius)
            or         (ii)                        ( being diameter)

Example:
            Find the cost of digging a well 3m in diameter and 24m in depth at the rate of Rs.10 per cu.m.

Solution:
            Given that

            Diameter of the well          
        Radius of the well,       
            Depth of the well,        
        Volume of the earth excavated
                                                             
                                                             
            Now, cost per cu. m    
       

Example:
            The volume of a cylindrical ring is 800 cu.cm. The radius of cross section is 2cm. Find the length of the ring.

Solution:
            Given that

            Radius of cross section,           
            Volume,                                   

            Let length of ring be     
            Now,