3.3 CPCTC and Circles Objective: After studying this lesson you will be able to apply the principle of CPCTC and recognize some basic properties of circles.
A C T CPCTC “Corresponding Parts of Congruent Triangles are Congruent” O D G Suppose that. Can we say that ? After we have proven two triangles are congruent we will use as a reason. Corresponding parts refer to the matching angles and sides in the respective triangles.
Point O is the center of the circle shown below. Definition of a circle:every point of the circle is the same distance from the center. O The center is not a part of the circle, just the outside or the “rim”. Circles are named by their centers. The circle above is named circle O or
P A B C Points A, B, and C lie on circle P. PA is called the radius PA, PB, and PC are called radii. Formulas to remember! Theorem:all radii are congruent
Given: Prove: StatementReason D B C A P
Given: Prove: Statement Reason R S T K O P M
Summary: When is it appropriate to use CPCTC as a reason in a proof? Homework: worksheet