Illustrative Mathematics
Lines of Symmetry for Triangles
What can symmetry tell us about triangles? After looking at four examples, learners will come to realize that lines of symmetry are different for equilateral, isosceles, and scalene triangles. Use this guided practice activity as an...
National Security Agency
Classifying Triangles
Building on young mathematicians' prior knowledge of three-sided shapes, this lesson series explores the defining characteristics of different types of triangles. Starting with a shared reading of the children's book The Greedy...
Curated OER
Toothpick Triangles
Students draw a chart (included in the lesson) to use with their investigation. They review terminology of triangles and receive toothpicks to use in the lesson. Beginning with three toothpicks, students form a triangle. They complete...
Virginia Department of Education
Classifying Angles
Don't be obtuse, this geometry unit is the just the right resource for educating the acute young minds in your class. From classifying and measuring angles, to determining the congruence of shapes, this...
Illustrative Mathematics
All vs. Only Some
All shapes have certain defining attributes that set them apart from others. In order to understand this, young mathematicians look at examples and non-examples of triangles, rectangles, and squares, working as a whole class to create...
Curated OER
Geometry and Quilting
Students create a quilt square for a class quilt using at least three, two-dimensional geometric figures. They research and write a brief description of at least two different quilt patterns that they find. Pupils discuss that quilts are...
Aurora City School District
Do Not Try to Kid a Kidder: The Art of Persuasion
The power to convince others of your argument lies in your knowledge of rhetoric! A thorough packet covers the basics of persuasion, including logical appeals and fallacies, and applies strategies to letters to the editor,...
Curated OER
Powerful Polygons
Students scan the classroom to find different common shapes. They listen as the teacher defines polygon and regular polygon. The teacher demonstrates regular polygons via the Internet and the "Math is Fun" web site. Students go outside...