1. Congruent Triangles You identified and used congruent angles. Name and use corresponding parts of congruent polygons. Prove triangles congruent using the definition of congruence.

2. If two geometric figures have exactly the same shape and size, they are congruent. Un two congruent polygons, all of the parts of one polygon are congruent to the corresponding parts or matching parts of the other polygon. These corresponding parts include corresponding angles and corresponding sides. Vocabulary

3. The Right Match CongruentNot congruent A B C D E F

4. Corresponding sides and angles Corresponding AnglesCorresponding sides AB C R S T AB RS BC ST AC RT

6. A B C H J K

7. The support beams on the fence form congruent triangles. In the figure ΔABC  ΔDEF, which of the following congruence statements correctly identifies corresponding angles or sides? A. B. C. D.

8. The phrase “if and only if” in the congruent polygon definition means that both the conditional and its converse are true. So, if two polygons are congruent, then their corresponding parts are congruent. For triangles, Corresponding parts of congruent triangles are congruent, or CPCTC. CP CTC