As I was sitting in my car at a red light the other day, I happened to look over to my right and the car next to me had a sign in the window:
“Do not open the door on this side. It is broke.”
The correct usage would be: “It is broken.”
Another option: “Someone broke this door.”
“Broke” is a verb (well, mostly it’s a verb. It is also popularly used as an adjective, commonly used to mean “out of money”–but in the above example with the car door, it’s a verb, b/c I doubt that the person who wrote the note on the door meant that the car door was out of money. LOL).