The teacher would not have told you that if he read some of the post on different Mustang fourms, do some searching around under, hand brake, e-brake, emergency brake, parking brake. This parking brake picture is not a good one. What blows me away I don't see many fixes.
If you dont want to chance your car rolling away, use both. Right now I'm on the brick system.
I think everybody on here uses their Parking Brake. We were debating if you leave it in gear or not when you park the car. Using the Parking Brake either way.