When the edge of the emerging shadow and the end of the stick were pulled by the rope, the top of the resulting triangle was 7.2 degrees. The reason for this shadow is that the city of Alexandria is located north of the equator north of the Earth. The city of Saigon, which now has no shadow from the well, is located very close to the equator. But in hindsight, that’s not the case. This is because a person who is just thinking will easily conclude that the shadow is coming from the side of the sun, not in the middle. But the problem is not that simple.