why are all the planets round and not differnt shapes?

Question: why are all the planets round and not differnt shapes?
- Keywords:
  planet,
  round,
  shape,
  space,
  stars
Asked by safia to Katie on 13 Jun 2011.
- Katie Marriott answered on 13 Jun 2011:
  
  This is because of gravity! Gravity is a force and therefore is must point in a direction. A planet is round because the gravity from any part of that planet points into the middle, and so a sphere is created.

Question: why are all the planets round and not differnt shapes?