Which set of angles has the same terminal arm as 70 degrees?

Answer: B = B ∈ {70° + n*360° I n ∈ Z } where Z is the set of the integer numbers.

Step-by-step explanation:

If we have an angle A, the other angles that have the same terminal arm than A can be written as:

B = A + n*360°

Here B is a "coterminal" angle to A. (they have the same terminal side)

where n can be any integer number (if n = 0 we have A = B, which is trivial, this means that any angle can be coterminal with itself.)

So we can write the set as:

B = B ∈ {70° + n*360° I n ∈ Z }