As I'm working from my apartment, can I just take this opportunity to say

"Hi honey, I'm home!"

(Apologies.)

Any way...

1A and 1B are correct. Though I must say that it is quicker to use the equivalent equation: where s is the arc length, r is the radius, and is the angle is radians.

2. Your answer here is correct for the positive answer. Now you need a negative version.

3. <-- This step is to reduce the angle to something easier to work with.

-Dan