Understanding Congruent Triangles: Key Concepts and Correspondence
This lesson on congruent triangles introduces the concept of congruent figures, which are two shapes that have the same size and shape. We learn that if two figures are congruent, their corresponding parts—angles and sides—are also congruent. The lesson details how to identify and name corresponding vertices, ensuring the triangles are compared accurately. Through examples, we explore different methods of establishing congruence between triangles and polygons, reinforcing the principle that congruent shapes maintain equivalence in size and form.
Understanding Congruent Triangles: Key Concepts and Correspondence
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Presentation Transcript
Congruent Triangles Lesson 4-2 Lesson 4-2: Congruent Triangles
Congruent Figures Congruent figures are two figures that have the same size and shape. IF two figures are congruent THEN they have the same size and shape. IF two figures have the same size and shape THEN they are congruent. Two figures have the same size and shape IFF they are congruent. Lesson 4-2: Congruent Triangles
A C B P R Q Congruent Triangles - CPCTC Corresponding Parts of Congruent Triangles are Congruent CPCTC: Two triangles are congruent IFF their corresponding parts (angles and sides) are congruent. = │ Vertices of the 2 triangles correspond in the same order as the trianglesare named. ≡ A ↔ P; B ↔ Q; C ↔ R Corresponding sides and angles of the two congruent triangles: = │ ≡ Lesson 4-2: Congruent Triangles
C B Z A X Y Congruent Triangles Z A ____ = Y B _____ ≡ │ ≡ │ X C ______ = Note: ∆ ZYX ∆ABC ______ ∆ABC ∆XYZ Lesson 4-2: Congruent Triangles
Example………… When referring to congruent triangles (or polygons), we must name corresponding vertices in the same order. S U N R A Y R SUN RAY Y A N Also NUS YAR U Also USN ARY S Lesson 4-2: Congruent Triangles
Example ……… If these polygons are congruent, how do you name them ? P O U N M E S A T R • Pentagon MONTA Pentagon PERSU • Pentagon ATNOM Pentagon USREP • Etc. Lesson 4-2: Congruent Triangles
