Object Rotation Detection

I need help making a c# code that will detect if a Pin in my bowling Game is knocked over by detecting if the pin’s transform rotation has been changed (then add +1 score).
I’m also very new to programming.

Assuming your bowling ball pin is of standard bowling pin shape and size:

Have an object at the very top of the pin, and another that specifies the cross section which the apex sits on. If the top of the pin is ever below any apex of the neck, then it has theoretically fallen over.

Although the 2nd pin has also theoretically fallen over, this apex detection will say that it hasn’t. However, because it is hypothetically guaranteed to fall over, we can assume that the apex detection will eventually say that it has indeed fallen over.