4.2 Congruent Figures In congruent figures, all corresponding parts of one figure are congruent to the corresponding parts of the other. Corresponding Parts: the segments and angles that match up from one figure to another.

Naming congruent figures Congruent figures are named by their Corresponding parts.

ATRQB is congruent to KLOVE Identify the corresponding congruent parts. <A ≡ <K <T ≡ <L <R ≡ <O <Q ≡ <V <B ≡ <E AT ≡ KL BQ ≡ EV RQ ≡ OV TR ≡ LO AB ≡ KE If congruent figures are named correctly, corresponding parts can be determined by the name without a picture.

All corresponding parts are congruent. By definition of congruent figures, the two triangles are congruent.

Third angles theorem If two angles of a triangle are congruent to two angles of another triangle, then the third angles are also congruent. Reflexive, Symmetric, and Transitive properties of Congruent triangles are true.

Hint: we only have one way right now to prove that triangles are congruent----- that is the definition of congruent. (Show that all the corresponding parts are congruent.)

Again, you had to show that all six pair of corresponding parts are congruent to prove that the triangles are congruent by definition of congruent triangles.

Geometry Page 228 (1-14, 36-40) Page 228 (15-35) extra credit 22, 32