a circle out of 3 points | GEOMETRIC PRINCIPLE of the week

Through three points not in a straight line, one circle and only one can be passed.

three nonlinear points circle passed drawn definedI got the exact wording of this geometric principle from A Beka Book's Plane Geometry by F. Eugene Seymour, a book I used in my eleventh grade geometry class. In the text, this principle is found on page 166 as a corollary to Construction 12 (the construction of a circle around a triangle). Something about this corollary intrigued me, and it's one of those random facts I never forgot.

"A circle is a round straight line with a hole in the middle." 
a schoolchild (quoted by Mark Twain)

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