Standard 1: Classify two-dimensional figures and three-dimensional figures based on defining attributes.

Students are asked to classify quadrilaterals and trapezoids by their properties.

Type: Formative Assessment

Using shape attribute clues, the student will determine shapes that fit these clues and describe a category to which they both belong.

Type: Formative Assessment

Students are asked to sort shapes using a Venn diagram and to determine the label for each section of the diagram.

Type: Formative Assessment

Using shape attribute clues, the student is asked to determine two shapes that fit these clues and describe a category to which both belong.

Type: Formative Assessment

Students are shown three triangles that fit a rule (each has a right angle) and are asked to determine which of three other triangles also fit the rule.

Type: Formative Assessment

Students discuss the attributes of squares and rhombuses and consider how these two shapes are related.

Type: Formative Assessment

Students are given a diagram of quadrilaterals that have been sorted and are asked to determine how the shapes were sorted. Then, students are given two additional quadrilaterals and asked to place them into the appropriate region on the diagram.

Type: Formative Assessment

Students are asked to describe the defining attributes of parallelograms and to consider the relationship between rectangles and parallelograms.

Type: Formative Assessment

Students are asked to consider how the hierarchy of quadrilaterals would change based on the two different definitions of trapezoids.

Type: Formative Assessment

Students are asked to use shape descriptions to sketch shapes and explain why some cannot be sketched.

Type: Formative Assessment

In this lesson, you will find clip art and various illustrations of polygons, circles, ellipses, star polygons, and inscribed shapes.

Type: Image/Photograph

In this lesson students will use standards-based quadrilaterals and triangles to design a roller coaster tower. Students will use the Engineering Design Process to work through the processes in this lesson.

Type: Lesson Plan

In this lesson, students will identify and classify triangles. In addition, students will demonstrate how to solve problems requiring attention to approximation, selection of appropriate measuring tools, and precision of measurement using triangles.

Type: Lesson Plan

"Where in the Venn are the Quadrilaterals?" is an activity that helps the student to develop a better understanding of classifying two-dimensional figures in a hierarchy based on properties.

Type: Lesson Plan

Students work together as a class and in small groups to classify quadrilaterals.

Type: Lesson Plan

Students will construct several simple polyhedra, then count the number of faces, edges, and vertices. These data should suggest Euler's formula. 

Type: Lesson Plan

This lesson can be used as an introduction - unit attention grabber- or as a final review on quadrilaterals. As the class forms a Sonobe cube, the different quadrilaterals are formed with each new fold. Included is a Power Point introduction with instructions, a video I made demonstrating how to fold the unit origami design, a video of my introduction lesson  to quadrilaterals and 2 worksheets which accompany the lesson. I enjoy doing this activity each year and am amazed at all the prior knowledge the students have retained as the lesson proceeds.

Type: Lesson Plan

The student will be engaged in a paper plane making activity while discovering the attributes of different triangles. The students will learned the similarities and differences of the following triangles: scalene, isosceles, equilateral, right, obtuse, and acute.

Type: Lesson Plan

Explore the defining attributes of trapezoids--a special type of quadrilateral--and classify them using diagrams in this interactive tutorial. You'll also learn how two different definitions for a trapezoid can change affect classifications of quadrilaterals. 

This part 6 in a 6-part series. Click below to explore the other tutorials in the series. 

Part 1: "Figuring Out" 2D Figures

Part 2: Exploring Relationships with Venn & Euler Diagrams

Part 3: Classifying Triangles by Angles Using Euler Diagrams

Part 4: Classifying Triangles by Sides & Angles Using Venn and Euler Diagrams

Part 5: Quadrilaterals

Type: Original Student Tutorial

Learn how to classify quadrilaterals--including parallelograms, rectangles, rhombi, and squares--based on their defining attributes using diagrams in this interactive tutorial.

This is part 5 in a 6-part series. Click below to explore the other tutorials in the series. 

• Part 1: "Figuring Out" 2D Figures
• Part 2: Exploring Relationships with Venn & Euler Diagrams
• Part 3: Classifying Triangles by Angles Using Euler Diagrams
• Part 4: Classifying Triangles by Sides & Angles Using Venn and Euler Diagrams
• Part 6: (Coming Soon)

Type: Original Student Tutorial

Learn how to show relationships represented in Venn & Euler Diagrams as you complete this interactive geometry tutorial.

This is part two of four. Click below to open the other tutorials in the series.

• Part 1: "Figuring Out" 2D Figures - Part 1
• Part 2 Exploring Relationships with Venn & Euler Diagrams
• Part 3: Classifying Triangles by Angles using Euler Diagrams
• Part 4: Classifying Triangles by Sides and Angles using Venn and Euler Diagrams

Type: Original Student Tutorial

Learn how triangles can be sorted and classified using side lengths and angle measures in this interactive tutorial.

This is the final tutorial in a four-part series. Click below to open the other tutorials in the series.

• Part 1: "Figuring Out" 2D Figures - Part 1
• Part 2 Exploring Relationships with Venn & Euler Diagrams
• Part 3: Classifying Triangles by Angles using Euler Diagrams
• Part 4: Classifying Triangles by Sides and Angles using Venn and Euler Diagrams

Type: Original Student Tutorial

Learn to classify triangles and use Euler diagrams to show relationships, in this interactive tutorial.

This is part-three of four. Click below to open the other tutorials in the series.

• Part 1: "Figuring Out" 2D Figures - Part 1
• Part 2 Exploring Relationships with Venn & Euler Diagrams
• Part 3: Classifying Triangles by Angles using Euler Diagrams
• Part 4: Classifying Triangles by Sides and Angles using Venn and Euler Diagrams

Type: Original Student Tutorial

Explore 2D (two-dimensional) figures and see how every 2D figure possesses unique attributes in this interactive tutorial.

This is part one of four. Click below to open the other tutorials in the series.

• Part 1: "Figuring Out" 2D Figures - Part 1
• Part 2 Exploring Relationships with Venn & Euler Diagrams
• Part 3: Classifying Triangles by Angles using Euler Diagrams
• Part 4: Classifying Triangles by Sides and Angles using Venn and Euler Diagrams

Type: Original Student Tutorial

Unlock an effective teaching strategy for teaching students to estimate angle measurements in this Teacher Perspectives video for educators.

Type: Perspectives Video: Teaching Idea

Unlock an effective teaching strategy for helping students make connections in mathematics using the Double Bubble Diagram in this Teacher Perspectives video for educators.

Type: Perspectives Video: Teaching Idea

This activity provides students an opportunity to recognize these distinguishing features of the different types of triangles before the technical language has been introduced. For finding the lines of symmetry, cut-out models of the four triangles would be helpful so that the students can fold them to find the lines.

Type: Problem-Solving Task

This task provides students a chance to experiment with reflections of the plane and their impact on specific types of quadrilaterals. It is both interesting and important that these types of quadrilaterals can be distinguished by their lines of symmetry.

Type: Problem-Solving Task

The purpose of this task is for students to measure angles and decide whether the triangles are right or not. Students should already understand concepts of angle measurement  and know how to measure angles using a protractor before working on this task.

Type: Problem-Solving Task

This lesson is designed to introduce students to quadrilaterals and the terms and properties associated with quadrilaterals. This lesson provides links to discussions and activities related to quadrilaterals as well as suggested ways to integrate them into the lesson. Finally, the lesson provides links to follow-up lessons designed for use in succession with the current one.

Type: Teaching Idea

This Khan Academy tutorial video presents examples and explanations for categorizations of perpendicular sides and right, obtuse, and acute triangles.

Type: Tutorial

In this Khan Academy tutorial video triangles are categorized by angles or side lengths of a specified size.

Type: Tutorial

This Khan Academy tutorial video introduces quadrilaterals. their categories, and subcategories.

Type: Tutorial

In this interactive, self-guided unit on 3-dimensional shape, students (and teachers) explore 3-dimensional shapes, determine surface area and volume, derive Euler's formula, and investigate Platonic solids. Interactive quizzes and animations are included throughout, including a 15 question quiz for student completion.

Type: Unit/Lesson Sequence