Answer:
Step-by-step explanation:
The transformations you want are ...
Taken together, these make the transformation ...
 (x, y) â (-y+6, -x-1)
So, your points become ...
 A(0, 0) â A'(6, -1)
 B(8, 1) â B'(5, -9)
 C(5, 5) â C'(1, -6)
___
The attachment shows the original triangle in red and the progression to the final triangle in blue.