UPDATE 2014-01-15: The current version of this Mathcad Prime 3.0 worksheet (along with a .pdf copy for users of older versions of Mathcad) can be found in the Civil Engineering section. This version (i.e. in the main documents section) will not be updated further.--FEL
Here is another surveying/civil engineering worksheet. This worksheet finds the center and radius of the unique circle that passes through three known points. The technique used finds the coefficients of the equation of circle (alternate form) using determinates.
BTW, I welcome comments, corrections, etc on all my worksheets.