| Nominativ | triangulum, triangulum, triangulus, triangula, triangula, triangulus | triangulae, triangulae, trianguli, trianguli, triangula, triangula |
| Genitiv | trianguli, trianguli, trianguli, trianguli, triangulae, triangulae | triangulorum, triangulorum, triangulorum, triangulorum, triangularum, triangularum |
| Dativ | triangulae, triangulo, triangulo, triangulo, triangulo, triangulae | triangulis, triangulis |
| Akkusativ | triangulam, triangulam, triangulum, triangulum, triangulum, triangulum | triangulos, triangulos, triangulas, triangulas, triangula, triangula |
| Ablativ | triangulo, triangulo, triangulo, triangula, triangula, triangulo | triangulis, triangulis |
| Vokativ | triangulum, triangule, triangule, triangulum, triangula, triangula | triangulae, triangulae, trianguli, trianguli, triangula, triangula |
