Illustrative Mathematics
Lines of Symmetry for Quadrilaterals
Explore how lines of symmetry help define different categories of quadrilaterals. Looking at a square, rectangle, trapezoid, and parallelogram, young mathematicians discover that each shape has its own, unique symmetry. Encourage your...
Illustrative Mathematics
What is a Trapezoid? (Part 1)
Challenge your class to construct a definition for trapezoids. Looking at four examples and four non-examples, students individually create definitions and use them to classify an unknown shape. Allow for small group and whole-class...
Illustrative Mathematics
What Shape Am I?
Sharpen your pencil and grab a ruler, it's time to draw some quadrilaterals! Given the definition of a parallelogram, rectangle, and rhombus, learners draw examples and nonexamples of each figure. The three definitions are...
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...
Education Development Center
Finding Parallelogram Vertices
Four is the perfect number—if you're talking about parallelograms. Scholars determine a possible fourth vertex of a parallelogram in the coordinate plane given the coordinates of three vertices. They read a conversation...
Texas Instruments
Texas Instruments: Classifying Quadrilaterals
Students will be sent ordered pairs through lists using the TI-Navigator. These pairs will then be graphed as a line graph and students will classify the shape of the quadrilateral and justify their choice.
Texas Instruments
Texas Instruments: Classifying Quadrilaterals
Students receive two Cabri Jr. files of quadrilaterals on a coordinate plane. They use their knowledge of quadrilaterals to give each one the most precise name. They may find the length and/or slope of the sides using the measuring tools...
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.
CK-12 Foundation
Ck 12: Parallelogram Classification
[Free Registration/Login Required] Students will use the classify different shapes by changing the points on the given shape. Click learn more to watch a video and click challenge me to answer a practice question.
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.