Final answer:
When parking a manual car facing uphill, leave it in gear and apply the handbrake; for an automatic, leave it in 'park'. Additionally, turn the wheels away from the curb to prevent the vehicle from rolling into traffic.
Step-by-step explanation:
When you have parked your car facing up a steep hill, and you have a manual vehicle, you should leave the car in gear and apply the handbrake to ensure it doesn't roll backwards. This is a precautionary measure to prevent the vehicle from moving if the handbrake fails. For an automatic transmission vehicle, leaving the car in 'park' will engage the parking pawl to prevent the wheels from moving, which secures the vehicle. Regardless of transmission type, you should also turn the wheels away from the curb so that if the vehicle does roll, it will roll away from the road and into the curb, helping to stop the vehicle.