why should you point a car’s wheels toward the curb when parking on a hill?

Question: why should you point a car's wheels toward the curb when parking on a hill?
- Keywords:
  car,
  parking
Asked by thing2oxo to Ed, Hayley, Jason, Nathan, Sophie on 15 Mar 2013.
- Sophie Holles answered on 15 Mar 2013:
  
  So if someone pushes it or the handbrake fails the car doesn’t roll into the road, it can’t move very far.

Question: why should you point a car's wheels toward the curb when parking on a hill?