Three noncollinear points in the xy-plane determine a circle. What is the radius of the circle determined by the points (1, 2), (-1, 2), and (2, 1)? A. √5 b. 5 c. 5√5 d. 25? - Quora
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How to Write the Equation of a Circle & Identify Points That Lie on the Circle | Geometry | Study.com
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