Unit 2:

Proofs about Congruence

How do we know when two geometric figures are congruent?
6 weeks

Unit two is about proving the congruence of angles, sides, and triangles and using these congruent relationships to prove properties of parallel lines, triangles, and other polygons. Throughout the unit, students make conjectures from a set of examples and nonexamples, and justify or refine these claims by reasoning inductively using the tools studied in unit one, which include constructions and transformations. Students learn to prove their justifications more formally by reasoning deductively and writing formal proofs. Therefore, proof should be a manifestation of student sense-making and logical reasoning —NOT a procedure.

Essential Questions:

  • How do we know when two geometric figures are congruent?
  • How do we prove a statement is true about parallel lines, triangles, quadrilaterals, and other polygons?
Printable Unit Plan
  • Geometry Unit Plan for Unit 2
    Geometry Unit Plan for Unit 2

    This is a printable version of the entire unit plan. You can make a copy of it and edit it or download and print it as needed.

Unit Outline

9 Components

Every unit begins with an Initial Task and ends with a Balanced Assessment, both focusing on core mathematics of the unit. The core mathematics is developed through a series of resources around Big Ideas; as you move through the unit, keep students focused on how these ideas are connected and how they address mathematical problem solving. Before attempting the Balanced Assessment, students have an opportunity to synthesize their knowledge through a multi-day Formative Assessment Lesson and teacher-designed re-engagement lessons.

Initial Task See 1 itemHide 1 item

Formative Assessment Lesson See 1 itemHide 1 item

Re-engagement See 1 itemHide 1 item

Balanced Assessment See 1 itemHide 1 item