Chapter 13

Properties of Triangles and Four-sided Figures

Chapter Introduction
Lesson 13.1 Classifying Triangles
Lesson 13.2 Measure of Angles of a Triangle
Lesson 13.3 Right, Isosceles, and Equilateral Triangles
Lesson 13.4 Triangle Inequalities
Lesson 13.5 Parallelogram, Rhombus, and Trapezoid
Critical Thinking Skills: Put on your thinking cap
Chapter Review
Chapter 13 Test Prep


Chapter 13: Properties of Triangles and Four-Sided Figures

This section shows you how to classify shapes from triangles to quadrilaterals – properties and types.

Chapter 13: Properties of Triangles and Four-Sided Figures (Quadrilaterals only)

This section of Khan Academy offers lessons on quadrilaterals only – properties and types of quadrilaterals.

***************Three Dimensional Shapes

This section offers lessons on how we measure volume using unit cubes. It also shows you a lesson on volume of a rectangular prism or box.

WEBSITE SUPPORT – classifying triangles + interactive model – quadrangles interactive model – triangle inequality theorem

***Additional Resources on Three Dimensional Shapes – click on shape: interactive prisms and pyramids with various bases – types of pyramids and more – click on shape: prismscylindersphere, cone – platonic solids (contains edges, faces, vertices, nets, and formulas for surface area and volume)