Name the genius Indian mathematician astronomer from the ancient world who was the first proponent of the round shape of the earth.

1. Pythagoras
2. Aryabhatta
3. Brahmagupta
4. Bhaskara

You are standing at a beach looking towards the horizon. You hear the horn of a ship. Which part of the ship will you see first?

1. Hull
2. Deck
3. Mast
4. All of them.

How can you prove that the earth is a sphere by looking at the horizon?

Briefly describe the shape of the earth. What is the specific name given to it?