22 Jan 2021

## Multiplication and Rotation

The following demo shows that multiplication (by a number distance one away from the origin) is the same as rotation.

Drag the red slider to rotate the point $$w$$. Click and drag the point $$z$$ to move it around.

The black $$+$$ represents the point $$z$$ rotated by $$a$$ degrees, while the purple $$\times$$ represents the product $$zw$$. They’re the same!