The ° symbol means "degrees." Any answer marked with that is definitely in degrees.
The technically correct thing to do is to assume that everything is in radians unless otherwise specified. However, humans tend to be bad at being technically correct, so if you haven't been told to use radians unless otherwise specified I would consider making contextual judgement calls. If you have been taught the technically correct rule, definitely use it. This interpretation agrees with the rules of thumb that I am about to give everywhere that it's applicable, leaving the last problem. I would guess that $42.5$ is supposed to be in radians, because everywhere else in the problem the professor has been careful to use the degree symbol, making me think its omission is deliberate. If none of the problems had been marked with a degree symbol, I might think otherwise since $42.5$ is much bigger than $2\pi$.
In contexts where you think your professor has simplified by opting to not use the degree symbol, some general rules of thumb can be applied. If it's unspecified and a $\pi$ shows up, you should assume radians. If it's unspecified and of the form $360/n$ for some integer $n$, use degrees. Another good rule of thumb is that if one interpretation gives an algebraic answer, use that interpretation. I'm unsure if that solves the last problem, though plugging it into Wolfram Alpha will tell you.