NOTE:

Glowing points on the canvas can be dragged,
as shown in this video clip:

Sine Wave

At every step, the red line is rotated by a small amount. The y-position of the red-line is used to draw the next vertical black line. This produces a sine wave.

Try dragging the point on the canvas. Also, try changing the step-count.

Box Rolling Along Line

Try moving the line points while the box is rolling.

Pythagoras' Theorem

This is a concrete instance of Pythagoras' theorem. It illustrates 3² + 4² equals 5².
Press START.

Long Division

Choose the numerator and denominator. Then press START.
An animated illustration is produced that explains long-division for those specific numbers. YouTube animations cannot do this.

Lens Simulation

Drag the green object. See how the red image changes.

Drag F₁ to change the focal length. Bring F₁ to the left of the lens to make it concave.