Scholastic
Scholastic: Max's Math Adventures: Max's Fantastical Zoo
Use this rhyming description of Max's Fantastical Zoo to make some amazing animals from geometric shapes. There is a teacher's guide for easy lesson planning.
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.
PBS
Pbs Mathline Lesson: Geometry, It's a Perfect Fit [Pdf]
This two-part geometry lesson plan has students identify, describe, and classify two-dimensional shapes. Students engage in hands-on activities including identifying shapes in the classroom, creating patterns with shapes, identifying...
Shodor Education Foundation
Shodor Interactivate: Shape Explorer: Area and Perimeter
An applet activity that provides an exercise in working with perimeter and area of 2D objects. The user is given a random figure and allowed to enter a value for the area and perimeter. Use the "How" and the "Why" button to assist you....