National Council of Teachers of Mathematics
The Math Forum: Line Symmetry
This site from The Math Forum is a great site if you are looking for activities to engage your students in learning about line symmetry. Peruse this collection of activities for one or two or four that would be right for your students....
National Council of Teachers of Mathematics
The Math Forum: Building a Pyramid
This Math Forum lesson gives instructions on how to build a paper pyramid. Bonuses included finding the surface area and volume of the pyramid.
University of Cambridge
University of Cambridge: Nrich: Net Cuts
In this enrichment game, the nets for nine solids are displayed. The twist is that each net has been cut into two pieces. The challenge is find the pieces that go together.
CK-12 Foundation
Ck 12: Interactive Geometry: 9.5 Modeling in Three Dimensions
Explore connections between a 2-dimensional net and a 3-dimensional box. Later in this section, use equations with variables to solve real world problems that use 2 and 3-dimensional objects.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Rhombus
This is a very brief look at the rhombus, which is a quadrilateral shape with four equal sides. Features include a JavaSketchpad that allows you to manipulate the shape.
Education Development Center
Think Math: Getting an Angle on Geometry [Pdf]
In this lesson on geometry and polygons, you use origami to use various polygons to make a heart. Included in this PDF lesson is vocabulary worksheet with answers provided.
University of Cambridge
University of Cambridge: Nrich: Symmetry Challenge
Sharpen your logic, symmetry, and pattern recognition skills while working on this challenge. Solution included.
University of Cambridge
University of Cambridge: Nrich: Count the Trapeziums (Trapezoids)
The challenge at this one page website, is to see how many trapezoids (British-trapeziums) you can find in the figure. When you have your results, you can easily check it right at the website.
University of Cambridge
University of Cambridge: Nrich: Christmas Presents
Improve your logic and net recognition skills with this learning game. Solution included.
University of Cambridge
University of Cambridge: Nrich: Making Boxes
Have fun and learn by making a box and then find out its maximum volume as well as other problem-solving activities, including making a table of your results and drawing a graph.
Curated OER
Bubbles
"What is so fascinating about bubbles? The precise spherical shape, the incredibly fragile nature of the microscopically thin soap film, the beautiful colors that swirl and shimmer, or most likely, a combination of all these phenomena?...
Khan Academy
Khan Academy: Quadrilaterals Review
After reviewing the properties of different quadrilaterals, students answer questions about each type.