How to determine the radius and center of a circle when only three noncollinear points are known?

Question

I am working on a C # program that deals with Oracle Spatial geometry. When circle data is stored in a geometry field, only three noncollinear points are saved to represent the circle. The problem is that I need to use this data on the Google Maps webpage and need a center point and circle radius (since my circle drawing function uses this information).

Can someone help with the math involved and translate the math to C #? I think this page may contain an answer, but it's hard for me to follow it. There are formulas for the radius and center given by three points, but then they define the variables as matrices, and I get lost at that point. How can I solve this in code?

Answer 1

m _r = m _t =

Center coordinates:

Courtesy of http://www.regentsprep.org/regents/math/geometry/gcg6/RCir.htm

Edit: The old link was dead.

Answer 2

, (28) - (34) . , (31) - (34) , . Wikipedia 3x3, .