Properties of Triangles and Four-sided Figures
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 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.
mathisfun.com – classifying triangles + interactive model
mathisfun.com – quadrangles interactive model
Khanacademy.com – triangle inequality theorem
***Additional Resources on Three Dimensional Shapes
education-portal.com – types of pyramids and more
mathisfun.com – platonic solids (contains edges, faces, vertices, nets, and formulas for surface area and volume)