# The angle of a vector: arg

### 13.14.11 The angle of a vector: arg

The arg command finds the angle of a complex number (the argument) or the angle of a vector defined by two points.

- arg takes one argument:
  v, a number or a vector defined by two points.
- arg(v) returns the argument of v if v is a complex number or the angle between the positive x direction and v if v is a vector.

#### Example.

Input:

arg(1+i)

Output:

π
4