Answer:
C
Step-by-step explanation:
Coterminal angles are angles that have a common terminal side.
So, given an angle θ, its coterminal angles will always be ±360°. This can be repeated.
We have a 645° angle.
Therefore, all values of the equation:
Where <em>n</em> is an integer is coterminal with our original angle.
Letting <em>n</em> = 1 and using the negative case, we acquire:
Therefore, an angle measuring 285° is coterminal with a 645° angle.
None of the other options can be reached by adding/subtracting 360.
Therefore, our answer is C.