# Complex number arithmetic and geometry

- Author:
- Chris Demouche, Dr Adrian Jannetta

- Topic:
- Arithmetic, Geometry

This applet is to show the relationship between arithmetic of complex numbers and the corresponding geometry on an Argand diagram.
Click and drag the points and . Check or uncheck the arithmetic operations in the right-panel.
In particular pay attention to the following:
and are shown to stop the app getting too crowded.

- Addition and subtraction of complex numbers works like vector addition and subtraction in the plane.
- Multiplication: the new complex number can be obtained by adding the arguments (angles) and multiplying the moduli (lengths).
- Division: the new complex number can be obtained by subtracting the arguments (angles) and dividing the moduli (lengths).