Answer: It always casts a curved shadow during a lunar eclipse
Explanation:
Aristotle concluded that Earth was round around 350 BC and also the same idea of a spherical Earth was found around 500 BC by Pythagoras.
Aristotle was the one who had this type of idea and thinking because he was watching the shadows.
Those shadows were curved and they were shown during a lunar eclipse which helped Aristotle with his idea of the Earth that is round and not flat.
