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