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| Greek alphabet | |
| Alpha | Beta |
| Gamma | Delta |
| Epsilon | Digamma |
| Zeta | Eta |
| Theta | Iota |
| Kappa | Lambda |
| Mu | Nu |
| Xi | Omicron |
| Pi | San |
| Qoppa | Rho |
| Sigma | Tau |
| Upsilon | Phi |
| Chi | Psi |
| Omega | Sampi |
Theta (upper case Θ, lower case θ) is the 8th letter of the Greek alphabet. In the system of Greek numerals it has a value of 9.
The lower-case letter θ is used as a symbol for: