Surface area of a cylinder

## As performed in real lab:

### Materials Required

Cylinder of known dimension, pair of scissors, gum, ruler.

### Procedure:

• Remove the top and bottom circles of the cylinder. [Fig(a)]
• Make a vertical cut in the curved surface and lay the cylinder flat. [Fig(b)]
• Measure the length and breadth of the rectangle so formed.  Fig(a)                                                      Fig(b)

## As performed in simulator:

• Create a right circular cylinder by providing radius for the base and height for the curved surface.
• Click on button "Draw Cylinder" to draw cylinder.
• Click on top & bottom to separate out the bases from top and bottom of the cylinder.
• Click on the cylinder to cut it and unroll to form a rectangle.

## Observations:

• The base and top of the cylinder are congruent circular regions.
• The curved surface area of the cylinder opens to form a rectangular region.
• The breadth of the rectangle is the height of the cylinder.
• The length of the rectangle is the circumference of the base of the cylinder.
• Curved surface area of cylinder(c)=area of rectangle

c= l x b

Since l= 2.π.r

b= h

c= l x b= 2.π.r.h

• Total surface area of cylinder = curved surface area (c) + 2 (area of base circle)

= 2.π.r.h + 2.π.r²

= 2.π.r (h + r)