Hi, I'm having trouble finding out whether I am doing my diagram the correct way or not. These are some of the properties of the diagram.

Make an ER diagram and tables of the diagram:
-Classroom contains the name of the building, the building number, and the space.
-Reservation contains the day, hours and the expected amount of space.
-Only the professor can reserve a room
-Each course contains name / id And professor.
-Each course must have a classroom
-Only one professor per course

I believe the Classroom and Course are the two entities and Reservation is the relation, also professor would be an attribute for course. For now I am not going to focus on the constraints and whatnot as I am in a hurry, but another way that has put doubts in my mind, is that the diagram is a ternary. Classroom, course, and professor are all entities connected to the relation Reservation, but that is what confuses me. Any tips or help would be appreciated, and if you need any more info let me know. In the meantime, I'm going to keep trying to figure it out. Thanks.