Function Euler

Euler(v: number, e: number, f: number): number
Calculates the Euler characteristic of a shape.
Parameters
- v: number
  The number of vertices
- e: number
  The number of edges
- f: number
  The number of faces
Returns number
Example
```
// Returns 2
const euler = Chalkboard.geom.Euler(8, 12, 6);
```
- Defined in Chalkboard.geom.ts:197