Setting the camera angle

I have a camera going around a circular walkway. Each 1/8th of the walkway is identical, so all I have to do is render the camera rotatiing around 1/8th of the way and loop it as many times as I want. I used some math (mostly the Law of Sines) to calculate the exact angle and position of my start frame and end frame. The problem is that I can’t apply my exact angle to the camera. Swift only lets me make inaccurate rotations with my mouse. Is there any way to enter in my angle with the keyboard?