What was the fisrt man to theorized that the eath was a sphere?

Answer 1

The first known individual to theorize that the Earth is a sphere was the ancient Greek philosopher Pythagoras, around the 6th century BCE. He proposed this idea based on observations of the Moon and stars. Later, philosophers like Plato and Aristotle supported this view with additional evidence, including the shape of the Earth’s shadow on the Moon during lunar eclipses. The concept was further solidified by Eratosthenes in the 3rd century BCE, who calculated the Earth's circumference.