Surface Area of a Cylinder

Date: 9/25/95 at 12:41:22
From: rcobb

What is the formula to calculate the surface of a cylinder 
with 25cm diameter and 20cm height?

Date: 9/25/95 at 14:28:7
From: Doctor Andrew

The surface area of a cylinder is the sum of the surface area of the top
and the bottom and the rest of the cylinder.  You could make a cylinder
with a piece of paper and two discs.  The discs would have 25cm diameters,
so you can find their area using area = pi * r * r.  What shape would 
the piece of paper need to be to make a 20cm cylinder with those discs? 
Once you know the shape of the paper you can calculate its area and add it
to the area of the disks.  See if this helps.  Good luck!

-Doctor Andrew,  The Geometry Forum