Fix the mistake: Congruence of Triangles
Congruence of Triangles ① Meaning of Congruence and Correspondence
Two figures are congruent if one can be moved, rotated, or flipped to fit exactly over the other. The symbols ≅ or ≡ are used.
Corresponding Sides and Angles
In congruent triangles, the lengths of corresponding sides are equal, and the measures of corresponding angles are equal.
Example ①
When △ABC ≅ △DEF, name the side corresponding to AB and the angle corresponding to ∠B.
Answer: AB ↔ DE (A↔D, B↔E). ∠B ↔ ∠E
When △ABC ≅ △DEF, name the side corresponding to AB and the angle corresponding to ∠B.
Answer: AB ↔ DE (A↔D, B↔E). ∠B ↔ ∠E
Key Points
- △ABC ≅ △DEF → The order of the vertices shows the correspondence
- Corresponding sides: AB=DE, BC=EF, CA=FD
- Corresponding angles: ∠A=∠D, ∠B=∠E, ∠C=∠F
Practice Problem
- When △PQR ≅ △XYZ, name the side corresponding to QR and the angle corresponding to ∠P.
Answer and Explanation
- Answer: QR ↔ YZ, ∠P ↔ ∠X.
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