Transformations

I think it depends. 

What course & unit was this in?  What were the exact problem instructions and wording?

I cannot really remember! But I think, the question was one of these questions, when they ask what the person solving the problem did wrong, or whether he or she missed anything, or they were simply right. So, they stating above, that Jack did not tell the direction of the rotation, which I found not true, because the sign of the angle itself tells us the direction of the rotation, right?

Like I wrote, I think it depends on context whether the sign of the angle tells the direction of the rotation.  Do you at least remember the course?  Was it 6th grade math or Trigonometry or ... ?

No! Unfortunately not!

Maybe it should be highlighted that (in two‐dimensional geometry) measuring an angle CCW (counter‐clockwise) is positive is a convention. The angle ∡𝑃𝐶𝑄 can mean

• the angle measured CCW from 𝑃 to 𝑄 around 𝐶
• the angle measured CW from 𝑄 to 𝑃 around 𝐶
• the angle measured CW from 𝑃 to 𝑄 around 𝐶
• the angle measured CCW from 𝑄 to 𝑃 around 𝐶

Convention means it is an unspoken rule that the first interpretation was “the” correct one. Technically – mathematically – all four options are equally valid.