A collection of 7 worksheets on the following topics:

• Types of Triangles. A worksheet on determining the type of a given triangle with respect to its interior angles (acute-angled, obtuse-angled, right-angled) and with respect to its sides (scalene, isosceles, equilateral).
• Triangle Angle Sum Theorem. A worksheet on the triangle exterior angle theorem. The exercises require to find missing angles by using the triangle exterior angle theorem.
• Exterior Angle Theorem. A worksheet on the triangle exterior angle theorem. The exercises require to find missing angles by using the triangle exterior angle theorem.
• Isosceles, Equilateral and Right-Angled Triangles. A worksheet on isosceles, equilateral and right-angled triangles
  and the angle properties of these triangles.
  Congruent Triangles Introduction. An introductory worksheet on congruent triangles. The exercises require to identify the corresponding equal angles or sides of some given congruent triangles.
• Congruent Triangles (SSS, SAS, ASA, AAS). A worksheet on determining whether triangles are congruent by Side-Side-Side (SSS), Side-Angle-Side (SAS), Angle-Side-Angle (ASA), or Angle-Angle-Side (AAS).
• Congruent right-angled triangles. A worksheet on deciding whether a given pair of right-angled triangles are congruent.
  Detailed solutions are included.

Looking for a comprehensive, no-prep collection of resources to help your secondary students master triangle properties, angle rules, and geometric proofs? This ultimate 7-lesson worksheet bundle provides a complete practice path, taking students from basic triangle classifications all the way to rigorous, multi-step congruence proofs!

Whether your classes are calculating missing values with algebraic equations or practicing formal proofs using SSS, SAS, ASA, and AAS, this resource has everything you need. Best of all, complete, step-by-step solutions are included for every problem to save you hours of marking time or to allow for easy student self-assessment!

What’s Included in This Bundle?
This package features 7 carefully structured resource packets (complete with full solutions) that scaffold student learning:

• Resource 1: Types of Triangles – Focuses on classifying triangles by their interior angles (acute-angled, obtuse-angled, right-angled) and side lengths (scalene, isosceles, equilateral) using numeric values and side markings.
• Resource 2: Triangle Angle Sum Theorem – Multi-level practice for finding the missing variable x inside a triangle. Problems range from basic arithmetic to advanced multi-step algebraic equations and vertically opposite angle setups.
• Resource 3: Exterior Angle Theorem – Students apply the exterior angle theorem to solve for x using single values, linear equations, and supplementary angle properties.
• Resource 4: Isosceles, Equilateral & Right-Angled Triangles – Deepens conceptual understanding of special triangle properties, base angle rules, and solving for missing values in isosceles right triangles.
• Resource 5: Introduction to Congruent Triangles – Students practice identifying corresponding equal sides and angles across matching congruent shapes.
• Resource 6: Congruence Concept Check**** – A rigorous True or False section testing deep conceptual knowledge of rigid transformations (rotations) and triangle types.
• Resource 7: Comprehensive Geometry Proofs – 11 distinct, diagram-based proofs where students analyse given markings, identify shared common sides, midpoints, heights, angle bisectors, and formally prove congruence using SSS, SAS, ASA, and AAS 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 complete criteria listings are provided for every problem, making marking or peer-assessment a breeze.
• Scaffolded Practice: Tasks build naturally from simple classification and value calculations to abstract, higher-level diagram analysis and formal proofs.
• Versatile Classroom Use: Perfect for main lesson tasks, independent classwork, homework assignments, cover work, or revision.

Skills Covered:

• Classifying triangles by side lengths and interior angles.
• Applying the Triangle Angle Sum and Exterior Angle rules algebraically.
• Working with geometric diagram properties: shared common sides, vertically opposite angles, midpoints, and angle bisectors.
• Proving triangle congruence using SSS, SAS, ASA, and AAS criteria.
• Verifying theorems regarding isosceles and equilateral triangle properties.

Curriculum & Key Stage Alignment:

• Key Stages: Key Stage 3 (KS3) Extension & Key Stage 4 (KS4) GCSE Maths
• Exam Board Suitability: Ideal for Higher Tier GCSE (AQA, Edexcel, OCR)
• Topic: Geometry and Measures -Congruence and Similarity -Geometric Proof & Angle Rules