| Answer | Crossword Clue |
|---|---|
| PTOLEMY | Second-century astronomer and mathematician |
| GAUSS | Renowned 19th-century German mathematician and astronomer |
| PTOLEMY | Influential second-century Greek astronomer and geographer |
| PTOLEMY | Second-century astronomer |
| PTOLEMY | Influential second-century astronomer |
| OMAR | Persian mathematician, astronomer and poet. |
