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....
Homeschool Math
Homeschool Math: Triangles
This lesson plan provides students with an opportunity to practice drawing and measuring triangles and angles. It also shows pictures and gives definitions of each type of angle and triangle.
National Council of Teachers of Mathematics
Nctm: Illuminations: Shape Cutter
This computer tool allows students to compose and decompose shapes by making cuts and rearranging the pieces. The tool has an exploration section for learning exercises.
Rice University
Rice University: Cynthia Lanius: Hidden Polygon Activity
On this site students are instructed to locate different types of polygons on triangle grid paper. This page can be printed so that students can actually draw them. It also gives a definitions link for each polygon.
Illustrative Mathematics
Illustrative Mathematics: G Gpe a Midpoint Miracle
For this task, young scholars are asked to draw a quadrilateral so that no two sides are congruent, no two angles are congruent, and no two sides are parallel. The task gives students the opportunity to prove that if we join the...