John Golden's: homepage
Java Sketchpad

I'm making an effort to both start translating some of the sketches I use for geometry education to Java Sketchpad, and to design new activities that transfer more easily. Java Sketchpad, while amazing, is much more limited than the original program. If you have thoughts on files that are here, or suggestions for new tasks please contact me . Each sketch has a link to the original sketchpad file.

The level of the activities will range from grade 3-12, although I mostly use them in teacher education courses.


  • Quadrilateral characteristics . An activity that identifies quadrilaterals by property rather than by appearance.


  • Triangle Explorations. A dynamic triangle, with all relevant measurements, and some type controls.

    Reasoning and Proof

  • Pythagorean Theorem . A visual proof based on an ancient Chinese proof.


  • Bag of Triangles. Given a bunch of triangles, can students identify which are similar?
  • Photoshop. This sketch allows students to compare dilations of common photo sizes to see if they're getting the whole picture.


  • Rotations . Given a rotated image and preimage, can you find the center of rotation?
  • Cat Puzzle. Use translation, rotation and reflection to get the image of a cat onto a target.
  • Motion Puzzles. Starting with a pentagon, identify the sequence of motions to get to different images. Practice in composition of motions, and recognizing that order matters!

    In case there was any question what a dweeb I am. I couldn't put up the java sketches without a java sketch.

    The mug is adjustable, in case you want a tall or a latte.

    Sorry, this page requires a Java-compatible web browser.

    These pages use JavaSketchpad , a World-Wide-Web component of The Geometer's Sketchpad . Copyright © 1990-2001 by KCP Technologies, Inc. Licensed only for non-commercial use.