CK-12 Foundation
Ck 12: Geometry: Polygons Study Guide
[Free Registration/Login may be required to access all resource tools.] This study guide focuses on polygons: convex vs concave, interior and exterior angles, and basic terminology for common polygons.
Khan Academy
Khan Academy: Classify Shapes by Line and Angle Types
Classify shapes based on pictures or attributes, such as angle types and side-lengths. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
CK-12 Foundation
Ck 12: Elem Math: Classify Objects as Rectangles, Squares, Circles, or Triangles
[Free Registration/Login may be required to access all resource tools.] Students practice classifying various two dimensional shapes as rectangles, squares, circles or triangles.
Texas Instruments
Texas Instruments: Classifying Triangles by the Length of the Sides Using Cabri
This activity uses Cabri Jr. to classify triangles according to the length of their sides. [Requires Adobe Reader.]
OER Commons
Oer Commons: Classifying Triangles
In this lesson, students learn to classify triangles by the size of the angles and the measures of the sides. Students will use interactives to explore equilateral, isosceles, scalene, acute, obtuse, and right triangles. Included are...
ClassFlow
Class Flow: Polygons
[Free Registration/Login Required] This flipchart introduces students to polygons and how to classify them.
Alabama Learning Exchange
Alex: "Polly"gon Pockets
Lesson plan that helps students explore the attributes of polygons through the use of cooperative groups. Students use jigsaw puzzles and foldable polygons. They also connect the attributes of specific polygons with objects in the real...
Math Is Fun
Math Is Fun: Regular 2 D Shapes
This tutorial provides illustrations for regular 2-D shapes as well as a definition for polygons and for regular polygons.
Curated OER
Edu place.com: Identifying and Classifying Polygons
This site describes intoductory elements on polygons and their properties.
National Council of Teachers of Mathematics
Nctm: Illuminations: Cutting Corners
Students will use their knowledge of plane figure attributes to create and view shapes by cutting and rotating shapes to stimulate discussions on names and attributes of various shapes they do not regularly encounter.
ClassFlow
Class Flow: Classifying Shapes
[Free Registration/Login Required] With this flipchart students will learn how to classify two-dimensional shapes and discuss the attributes of polygons.
Government of Alberta
Learn Alberta: Math Interactives: Exploring Shape Classification
Investigate the properties of triangles, quadrilaterals, and regular polygons using this interactive Learn Alberta math resource. Students are able to practice classifying shapes based on their different properties. Be sure to follow the...
Beacon Learning Center
Beacon Learning Center: Triangles Side by Side
This comprehensive web lesson describes how to classify triangles by their angle and side measurements. It provides real-world examples and exercises for students to practice the skill.
GeoGebra
Geogebra: Copy of Classify Two Dimensional Figures
User will drag the vertices of the quadrilaterals to decide on the best possible classification.
University of Regina (Canada)
University of Regina: Math Central: Lesson: Mr. Z's 5 Minute Game of Geometric Pandemonium
Students make a series of geometric drawings of points, obtuse angles, rays, polygons, and the like. Each child is given one but not allowed to show anyone else. The drawing is then taped to the back of the child in front of them. The...
PBS
Pbs Mathline Lesson: Geometry, It's a Perfect Fit [Pdf]
This two-part geometry lesson plan has learners identify, describe, and classify two-dimensional shapes. Students engage in hands-on activities including identifying shapes in the classroom, creating patterns with shapes, identifying...
NumberNut
Number Nut: Shapes, Symbols, and Colors: 2 D Shapes
Did you know that two-dimensional shapes are also called polygons? This lesson describes the various 2-D shapes and includes two interactive games to reinforce skills.
Alabama Learning Exchange
Alex: Geometric Man
The students will explore angles, rays, line segments, perpendicular lines, parallel lines, and two-dimensional figures through the use of the book Shape Up! Fun With Triangles and Other Polygons by David A. Adler. They will also...
BBC
Bbc: Bitesize: Maths: 2 D Shapes
Learn about the properties of 2-D shapes: circles, triangles, polygons, and quadrilaterals. Includes information, video, and examples about each, with games and quizzes for reinforcement.
CK-12 Foundation
Ck 12: Geometry: Quadrilateral Classification
[Free Registration/Login may be required to access all resource tools.] Recognize and classify quadrilaterals
CK-12 Foundation
Ck 12: Geometry: Parallelogram Classification
[Free Registration/Login may be required to access all resource tools.] Classify a parallelograms as a rhombus, rectangle, or square.
CK-12 Foundation
Ck 12: Geometry: Quadrilateral Classification
[Free Registration/Login may be required to access all resource tools.] This concept teaches students to classify quadrilaterals in the coordinate plane.
CK-12 Foundation
Ck 12: Geometry: Quadrilateral Classification
[Free Registration/Login may be required to access all resource tools.] Recognize and classify quadrilaterals
Alabama Learning Exchange
Alex: What Do We Have in Common?
This inquiry activity explores the definitions of quadrilaterals and the properties of the diagonals of quadrilaterals to classify quadrilaterals. Learners will work cooperatively to justify conclusions. This lesson plan was created by...