Geometry    

Polygons

Types of Triangles

Measuring Interior Angles

Exploring Area and Perimeter

cm2 grid paper

Area of Polygons

Worksheets for Area of: Triangles, Parallelograms, Trapezoids 

Introduction to the coordinate plane: http://mathforum.org/cgraph/cplane/

coordinate plane Maze Game  http://www.shodor.org/interactivate/activities/MazeGame/

Geometry U2 review

Finding Pi

Reflections using Measurement

Reflection by Measurement Activity

Playing with Rotations: http://nlvm.usu.edu/en/nav/frames_asid_299_g_3_t_3.html?open=activities

National Library of Virtual Manipulatives:  http://nlvm.usu.edu/en/nav/grade_g_3.html

Middle School Portal:  http://msteacher.org/epubs/math/circles/activities.aspx

http://www.shodor.org/interactivate/activities/Transmographer/

Transmographer 2:    Excellent tool for rotations, translations, reflections

Rotation http://www.bbc.co.uk/schools/ks3bitesize/maths/shape_and_space/transformations_1_3.shtml