Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum

Monthly Update sign up
Mailing List signup
Follow The Annenberg Learner on LinkedIn Follow The Annenberg Learner on Facebook Follow Annenberg Learner on Twitter
Learning Math Home
Patterns, Functions, and Algebra
Session 2 Part A Part B Part C Homework
Geometry Site Map
Session 2 Materials:

Geometry Session 2: Triangles and Quadrilaterals

In this session, you will build triangles and quadrilaterals to explore their properties. Classification is an important part of geometry and other areas of mathematics. By creating and manipulating triangles and quadrilaterals, you will develop a sense of logical classifications and how different figures are related.

In This Session:

Part A:

Different Triangles

Part B:

Linkage-Strip Constructions

Part C:

Building Towers



For information on required and/or optional materials for this session see Note 1.

Learning Objectives

In this session, you will learn the following:


How to classify triangles according to some of their features


A rule that describes when three given lengths will make a triangle and when they will not


A rule that describes when four given lengths will make a quadrilateral and when they will not


How to use what you've learned about geometry and the properties of figures to help with a construction task

video icon

Throughout the session you will be prompted to view short video segments. In addition to these excerpts, you may choose to watch the full-length video of this session.


Previously Introduced:

New in This Session:


perpendicular bisector

acute triangle
equilateral triangle
isosceles triangle
obtuse triangle
right triangle
scalene triangle
side-angle-side (SAS) congruence
side-side-side (SSS) congruence
similar triangles
triangle inequality

Next > Part A: Different Triangles

Learning Math Home | Geometry Home | Glossary | Map | ©

Session 2: Index | Notes | Solutions | Video

© Annenberg Foundation 2015. All rights reserved. Legal Policy