What shape does each planet take?

Answer 1

A planet is said to be in `hydrostatic equilibrium, its shape is formed roughly into a sphere by its own gravity. Most planets rotate enough for the sphere to flatten out ever so slightly, squashed at the centre, so really they are `oblate spheroids`.

Answer 2

Planets are roughly spherical in shape due to their gravity pulling the material inward, creating a balance between the forces pushing outward from within (such as heat and pressure) and gravity pulling inward. Some planets might have an oblate spheroid shape, meaning they are slightly flattened at the poles and bulging at the equator due to their rotation.