Triangle A'B'C' is apparently - у А A' B C С B' O A clockwise 90 degree rotation of Triangle ABC O A reflection across the y-axis of Triangle ABC O A translation of Triangle ABC right 7 units O A clockwise 270 degree rotation of Triangle ABC

Since all coordinates of the transformated triangle are changed like this:
[tex](x,y)\rightarrow(y,-x)[/tex]Triangle A'B'C' is a clockwise 270 degree rotation of triangle ABC
A counterclockwise rotation of 90º is the same that a clockwise rotation of 270º