El teorema d'Euler ens diu que C + V = A + 2
Ex: un tetraedre té 4 cares, 6 arestes i 4 vèrtexs.
4 + 4 = 6 + 2
| Animals | Alumnes | Freq.Absoluta (fi) | Freq.Relativa (hi) | Freq.Absoluta Acumulada | Freq.Relativa Acumulada |
| Gossos | 5 | 5 | 5/24= 0'21 | 5 | 5/24 = 0'21 |
| Gats | 6 | 6 | 6/24= 0'25 | 11 | 11/24 = 0'46 |
| Ocells | 4 | 4 | 4/24= 0'17 | 15 | 15/24 = 0'63 |
| Rossegadors | 6 | 6 | 6/24= 0'25 | 21 | 21/24 = 0'88 |
| Altres | 3 | 3 | 3/24= 0'13 | 24 | 24/24 = 1 |