WSP Proof Without Words Pythagorean Theorem

  • Proof Without Words: Pythagorean Theorem

    Grade: 6th to 8th

    Why is c2 = a2 + b2? Watch a dynamic, geometric "proof without words" of the Pythagorean Theorem. Can you explain the proof?



    How to Use

    Use the red points on the sliders to adjust the lengths of the sides of the triangle.


    • The buttons are meant to be used sequentially, and will appear in the order in which they are meant to be pressed.
      • Be sure to allow all movements to cease before pressing another button, as this will affect the performance of the sketchpad.
    • The Reset button will allow you to start over.



    • Why does this proof work? Construct a proof.
    • Do some research online to find other ways to prove the Pythagorean Theorem.


    Objectives and Standards

    NCTM Standards and Expectations
    • Geometry / Measurement
    • Understand that by similarity, side ratios in right triangles are properties of the angles in the triangle, leading to definitions of trigonometric ratios for acute angles.
    • 6-8
    • Geometry