Lesson plan

Classify triangles by examining their properties

teaches Common Core State Standards MP7 http://corestandards.org/Math/Practice/MP7
teaches Common Core State Standards MP3 http://corestandards.org/Math/Practice/MP3
teaches Common Core State Standards MP1 http://corestandards.org/Math/Practice/MP1
teaches Common Core State Standards 3.G.A.1 http://corestandards.org/Math/Content/3/G/A/1

Classify triangles by examining their properties

Big Ideas: We can classify two-dimensional shapes by their properties or attributes. Shapes with same attributes can be grouped to make a larger category. This lesson builds on students’ understanding that shapes in different categories may share attributes, and that the shared attributes can define a larger category. This task requires students to classify triangles by examining their attributes and what they know about properties. Students are presented with manipulatives which they have to use to create different triangles based on specific descriptions. By understanding these attributes and properties, students then are able to draw, describe and classify triangles, as they justify their work and their thinking. Vocabulary: attributes, triangle, acute, obtuse, scalene, equilateral, isosceles, angle, right angle, polygon, two dimensional, side, line segment, vertex, congruent Special Materials: Flat toothpicks Geoboard (optional) dot paper (optional) pattern blocks (optional) ruler (optional) AngLegs (optional) straws (optional)