# ALEX Classroom Resources

ALEX Classroom Resources
Subject: Mathematics (9 - 12)
Title: Geometry Module 1, Topic B: Unknown Angles
URL: https://www.engageny.org/resource/geometry-module-1-topic-b-overview
Description:

Constructions segue into Module 1, Topic B, Unknown Angles, which consists of unknown angle problems and proofs. These exercises consolidate students’ prior body of geometric facts and prime students’ reasoning abilities as they begin to justify each step for a solution to a problem. Students began the proof-writing process in Grade 8 when they developed informal arguments to establish select geometric facts (8.G.5).

Subject: Mathematics (9 - 12), Mathematics (9 - 12)
Title: Geometry Module 1, Topic E: Proving Properties of Geometric Figures
URL: https://www.engageny.org/resource/geometry-module-1-topic-e-overview
Description:

In Module 1, Topic E, students extend their work on rigid motions and proofs to establish properties of triangles and parallelograms. In Lesson 28, students apply their recent experience with triangle congruence to prove problems involving parallelograms. In Lessons 29 and 30, students examine special lines in triangles, namely, midsegments and medians. Students prove why a midsegment is parallel to and half the length of the side of the opposite triangle. In Lesson 30, students prove why the medians are concurrent.

Subject: Mathematics (9 - 12), Mathematics (9 - 12)
Title: Geometry Module 1, Topic G: Axiomatic Systems
URL: https://www.engageny.org/resource/geometry-module-1-topic-g-overview
Description:

In Module 1, Topic G, students review material covered throughout the module. Additionally, students discuss the structure of geometry as an axiomatic system.

ALEX Classroom Resources: 3