Reflect the given triangle over the line y=x.

Answer:
3
Step-by-step explanation:
This task is about reflecting the numbers you have given. So if you had 3 and -3 in the first point, the second one is -3 and 3, following 6 and 3 is reflecting 3 and 6. Finally 3 and 3 reflection is 3 and 3 :)