Q. A cylinder of radius and height both equal to 10 cm. made by paper is unfolded to form a plane sheet of paper. If circumference of a circle is 2*Pi*R, then area of plane paper sheet is-

Options
1) 100 Pi
2) 400 Pi
3) 300 Pi
4) 200 Pi
5) 20 Pi
6) 10 Pi
7) 40 Pi
8) 2 Pi
9) 5 Pi
10)None of these

• When we unfold a cylinder
  height=breadth of paper
  circumference=length of paper
  area is l×2*Pi*R = 10×2*Pi*10 = 200*Pi
  
  
• 10 years agoHelpfull: Yes(3) No(0)
• lenght becomes the circumference of circle(2*pi*R)
  area=l*b
  =10*2*pi*10
  =200*pi
• 10 years agoHelpfull: Yes(1) No(0)
• unfolding,
  length= circumference=2*10*pi=20pi cm
  breadth = height = 10cm
  Area = length * breadth = 200pi sq. cm (option 4)
• 10 years agoHelpfull: Yes(0) No(0)
• 200pisquare cm
• 10 years agoHelpfull: Yes(0) No(0)
• 200pi sq cm
• 10 years agoHelpfull: Yes(0) No(0)
• 100 pi,area of cylinder= pi*r*r=pi*10*10=pi*100=100pi
• 10 years agoHelpfull: Yes(0) No(0)