Detailed Instructions: You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For consistency, answers should be in all lower cased letters.
Q: Category: GEOMETRY
Clue: Because the Earth is flattened at the poles, it's this figure, having all its plane sections circle or ellipses
A:
a spheroid