Geometry 4-6 CPCTC
Definition Corresponding Parts of Congruent Triangles are Congruent (CPCTC) If two triangles are congruent, then all of their corresponding parts are congruent. You can only use CPCTC after you know that two triangles are congruent.
Example A landscape architect sets up the triangles shown in the figure to find the distance JK across a pond. What is JK? First, prove the triangles congruent. Second, use CPCTC to find JK.
Example x-2
Example Find the values of x and y. Given: PR bisects QPS and QRS. 125° x - 5° 12 2y - 4
Example If ∆DEF ∆GHI and DE = 25, EF = 30, and DF = 27, what is the value of GI? If ∆ABC ∆XYZ and AB = 12, BC = 35, AC = 40, and YZ = 5x + 5, what is the value of x?