I am looking for a software program in which I can input exterior
dimensions of, say, a house or a tract of land, and have it compute
the total area of the polygon. I'm having difficulty locating such a
program. Probably in some sort of real estate surveying or appraising
program, but I don't have any leads.

Thanks

This is a worksheet published by a teacher explaing how to get the
area of any polygon:

http://www.ship.edu/~eisen/Eisen02/HighSchool/Finding%20the%20Area%20of%20any%20Polygon.doc

Here is fortran source code to such a program, but requires you to
know a lot of information before it will calculate it:
http://www.ecse.rpi.edu/Homepages/wrf/misc_notes/area.html

But as you can see from this page
(http://www.math.tamu.edu/~dallen/digitalcam/poly1/poly1.htm), the
area of a polygon is not so easily calculated.  Your best bet is a
piece of paper and a pencil and dividing the polygon into triangles
and getting the area that way.

You can use a program called geometer sketchpad to solve all kinds of
geometry problems in a visual format.  It is not a real estate program
but a general geometry problem solver.  It is used in many high
schools and can be mastered with just a short tutorial.

  It can be purchased from http://www.keypress.com

Auto Cad or any engineering draughting program will calculate the area
of a polygon.  Heres a link to down load a free program.
http://www.btinternet.com/~kburnett/freecad.htm