I think that it's B, y = -x - 7 because first you'd subtract y to get it on the other side then add x and then you'd need to make the y positive so you would divide x + 7 by -1 and that would make it y = -x - 7.
The answer is C I had that same test question
If you are asking for the circumference of an arc (definition of arc is "a part of the circumference of a circle or other curve"), then the formula is:
x/360*r*2pi, where x is the angle in degrees and r is the radius.
note that if you want to find the circumference of the sector, the formula becomes
x/360*2*2pi + 2r,
where x is the angle in degrees and r is the radius.
