Shodor Education Foundation
Shodor Interactivate: Lesson: An Introduction to Quadrilaterals
Quadrilaterals-parallelograms, rectangles, and trapezoids-are thoroughly introduced in this lesson plan for upper elementary and middle school students. Lots of resources are linked to it to help support the teacher and students....
Math Is Fun
Math Is Fun: Interactive Quadrilaterals
Resize and rotate different types of quadrilaterals--square, rectangle, rhombus, trapezoid, and kite--while learning the definitions of these different shapes and labeling the angles and diagonals. CCSS.Math.Content.3.G.A.1 Understand...
National Council of Teachers of Mathematics
The Math Forum: What Is a Tessellation?
The Math Forum defines and illustrates geometric tessellation.
University of Georgia
University of Georgia: Inter Math: Parallelograms
This site gives the general definition of a parallelogram with examples and questions for the reader to ponder about characteristics of parallelograms. There are also links to related terms, everyday examples, challenging problems, more...
Cool Math
Coolmath: Coolmath4kids: Tessellations
Tessellations are explained and described at this website. Three basic rules are given for creating tessellations.
Science Struck
Science Struck: List of Different Types of Geometric Shapes
A comprehensive list of 2D shapes and 3D solids with everything from a triangle to a dodecahedron. Includes illustrations and short descriptions of attributes for each.
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.
GeoGebra
Geogebra: Copy of Classify Two Dimensional Figures
User will drag the vertices of the quadrilaterals to decide on the best possible classification.
Illustrative Mathematics
Illustrative Mathematics: 5.g What Is a Trapezoid? (Part 2)
The purpose of this task is for students to compare different definitions for trapezoids. Aligns with 5.G.B.4.
Illustrative Mathematics
Illustrative Mathematics: 4.g What Is a Trapezoid? (Part 1)
The purpose of this task is for students to articulate a definition for a trapezoid. Aligns with 4.G.A.2.
Illustrative Mathematics
Illustrative Mathematics: 4.g What Shape Am I?
In this task, students ultimately use the definitions they are given for three types of quadrilaterals and what they know about parallel sides to identify that a square fits all the definitions and explain why. Aligns with 4.G.A.2.
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.
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...
Alabama Learning Exchange
Alex: A What? A What? A Quadrilateral
In this lesson, students will identify the characteristics of a quadrilateral. Students will have a chance categorize quadrilaterals into subgroups such as squares, rhombuses, rectangles, and nonregular quadrilaterals. This lesson using...
Math Open Reference
Math Open Reference: Trapezoid
Learn about trapezoids with this helpful reference tool. Provides a detailed definition, examples, and interactive activities that enhance further explanation. Includes links to related topics.
Homeschool Math
Homeschool Math: Area of Triangles
This lesson presents the idea that the area of any triangle is exactly half of a certain parallelogram -- thus we get the familiar formula of multiplying the base and the altitude and taking half of that. The lesson contains varied...
Cuemath
Cuemath: Geometric Shapes
In this mini-lesson, you will learn about the definition of geometric shapes and view many examples. You can check out the interactive simulations to know more about the lesson and try your hand at solving a few interesting practice...
Math Open Reference
Math Open Reference: Polygon
A complete reference guide to polygons. It provides definitions, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Quia
Ixl Learning: Types of Quadrilaterals
Brush up on your math skills relating to the types of quadrilaterals then try some practice problems to test your understanding.
PBS
Pbs Learning Media: Classifying Polygons
This interactive diagram focuses on sorting polygons by common properties and then you select the correct label for each section of the Venn Diagram.
PBS
Pbs Learning Media: Pbs Kids: Odd Squad: Collection
Welcome to Odd Squad: the zaniest, craziest team of kid investigators around! Explore content below targeted at making elementary-level math a fun, imaginative experience, mixing concepts like arithmetic and geometry with fantastical...
Other
Nearpod: Mixed Review & Practice: Geometry
In this lesson on reviewing fifth-grade geometry concepts, 5th graders learn about the mathematical domain, explain why it is important, and complete a variety of practice problems.
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.
Wolfram Research
Wolfram Math World: Semiregular Tessellations
This one page Mathworld site has a number of examples of semiregular tessellations. A definition and a small amount of related information is given at the bottom of the page.