The frame of a lampshade is cylindrical in shape. it has a diameter 28cm and height 17cm. it is to be covered with a decorative cloth. a margin of 2 cm is to be given for its folding it over top and bottom of the frame. if 1/12 of cloth is wasted in the cutting and pasting, find how much cloth is required to be purchased for covering the frame.



The 2cm on each side add to the height. So new height would be 17+4=21=h. 
d=R/2 so radius is 14cm.
2*pi*R*h. use this formula. Take pi as 22/7 it divides with 14 and 21
so you get 1848cm2. 
Also, 1.5cm2 cloth is also wasted in cutting and pasting, so add that. You get 1848+1.5=1849.5cm2

Hope this helped