2016 Combo #4
Source:
December 30, 2016
Problem Statement
Let be the rectangle in the Cartesian plane with vertices at and . can be divided into two unit squares, as shown; the resulting figure has seven edges.[asy]
size(3cm);
draw((0,0)--(2,0)--(2,1)--(0,1)--cycle); draw((1,0)--(1,1));
[/asy]
How many subsets of these seven edges form a connected figure?