Regular hexagon abcdef rotates 240° counterclockwise about its center to produce hexagon a'b'c'd'e'f'. which points will a' and b' coincide with in the preimage? .

The correct answer to this question is points C' and D'

If I turn it 60 degrees counterclockwise, the A will be where F is
If i turn it 120 degrees counterclockwise, the A will be where E is..
If you continue this pattern,

The point C will coincide where A is before.
The point D will coincide where B is before.