Final answer:
The location of Raphia would be determined using historical and geographical analysis, comparing it to known locations such as Alexandria, which is at 31°N, 30°E.
Step-by-step explanation:
The coastal city of Raphia's location, in relation to Alexandria, which is at 31°N latitude, 30°E longitude, can be determined using historic records and map analysis. Eratosthenes, a philosopher from Alexandria, used differences in shadow lengths to calculate Earth's circumference, thereby contributing to our understanding of latitude and longitude.
Alexandria and Syene (Aswan) played key roles in his calculations, with the difference in Sun's zenith angle between the two cities being 1/50 of a full circle, or approximately 7.2 degrees. To find Raphia's coordinates, historians and geographers would examine ancient maps and texts to compare Raphia's described location to known locations like Alexandria. Since Raphia was a coastal city mentioned in historical accounts, its coordinates would be close to the Mediterranean coastline, north of Egypt, and to the east of Alexandria.