SUMS: Anderson -- Squaring the Square

Stuart Anderson this week will be talking about squaring the square.  From his website
(http://www.squaring.net/index.html) 

A square or rectangle is said to be ’squared’ into n squares if it is tiled into n
squares of sizes s1,s2,s3,..sn.  A rectangle can be squared if its sides are
commensurable (in rational proportion, both being integral mutiples of the same
quantity) The sizes of the squares si are shown as integers and the number of squares n
is called the order.