Diameter of a circle using 3 nonlinear points I am trying to find the diameter of a circle using 3 points on its circumference.  2 of the points are 5 feet from eachother while the third point is centered between the other 2.  The ceter point is 1 foot from a line drawn between the other 2 points.

So you have an arc whose chord is l=5 feet long and the sagitta is s=1 fooot.
See Wikipedia article http://en.wikipedia.org/wiki/Sagitta_(geometry) 
