Congruent Triangles worksheet (with solutions)

A worksheet on deciding whether a given pair of triangles are congruent. Detailed solutions are included.

Looking for a comprehensive, no-prep collection of resources to help your students master congruent triangles and geometric proofs? This packet (Problem Set 2) provides the ultimate practice path, taking students from basic side-by-side matching all the way to rigorous congruence analysis!

Whether your classes are just learning to identify corresponding parts or are practicing formal proofs using SSS, SAS, and ASA, this resource has everything you need. Best of all, complete, step-by-step solutions are included to save you hours of marking time or to use for easy student self-assessment!

What’s Included in This Resource?
This package features a carefully structured resource set (complete with full solutions) covering all aspects of triangle congruence:

• Section 1: Angle Measures of Congruent Triangles – Students use corresponding parts (SSS) and the Triangle Angle Sum rule to calculate missing interior angles across congruent pairs.
• Section 2: Congruence Condition Analysis – Deepens conceptual understanding by asking students to evaluate multiple mathematical cases to decide which side and angle combinations guarantee triangle congruence (and which are traps, like AAA).
• Section 3: Missing Congruence Data (Fill-in-the-Blank) – Students examine pairs of triangles and determine exactly what missing side length or angle constraint is required to prove they are identical.
• Section 4: Comprehensive Geometry Diagrams (Exercises a-g) – 7 distinct diagram-based problems where students analyse given markings, identify shared common sides, use vertically opposite angles, work with parallelograms, and determine congruence using SSS, SAS, and ASA rules.

Why Teachers Love This Resource:

• Ready to Print: Just download, photocopy, and you are ready to teach!
• Step-by-Step Answer Keys: Full calculations, geometric reasoning diagrams, and full criteria listings are included for every single problem, making marking or peer-assessment a breeze.
• Scaffolded Practice: Tasks build naturally from simple value calculations to abstract, higher-level diagram analysis.
• Versatile Classroom Use: Perfect for main lesson tasks, independent classwork, homework assignments, cover work, or revision.

Skills Covered:

• Matching corresponding vertices, sides, and angles.
• Applying the Triangle Angle Sum rule to find missing interior values.
• Identifying non-congruent traps (such as AAA or mismatched side locations).
• Proving triangle congruence using SSS, SAS, and ASA criteria.
• Working with geometric diagram properties: shared common sides, vertically opposite angles, and parallel side properties.