Answer:
A'(-1,-3)
B'(-2,-2)
C'(-4,-3)
Step-by-step explanation:
The rotation by 90° counterclockwise about the origin has the rule
[tex](x,y)\rightarrow (-y,x)[/tex]
So, the vertices of the triangle ABC have the images:
[tex]A(-3,1)\rightarrow A'(-1,-3)\\ \\B(-2,2)\rightarrow B'(-2,-2)\\ \\C(-3,4)\rightarrow C'(-4,-3)[/tex]
see attached diagram for details.