Triangle Congruence Criteria

50 Minute Class, Curriculum, Geometry

Learning Goal: Explore and develop understanding of what criteria is required for triangle congruence.



  • Common Core
    • HSG.CO.B.7 – Use the definition of congruence in terms of rigid motions to show that two triangles are congruent if and only if corresponding pairs of sides and corresponding pairs of angles are congruent.
    • HSG.CO.B.8 – Explain how the criteria for triangle congruence (ASA, SAS, and SSS) follow from the definition of congruence in terms of rigid motions.
  • TEKS
    • G.4(C) – verify that a conjecture is false using a counterexample
    • G.5(A) – investigate patterns to make conjectures about geometric relationships, including angles formed by parallel lines cut by a transversal, criteria required for triangle congruence, special segments of triangles, diagonals of quadrilaterals, interior and exterior angles of polygons, and special segments and angles of circles choosing from a variety of tools