Yes, the triangles in number 3 are congruent using SSS because all of the sides have the congruent markings.
Let, coordinate of point A' is (x,y).
Since, A' is the symmetric point A(3, 2) with respect to the line 2x + y - 12 = 0.
So, slope of line containing A and A' will be perpendicular to the line 2x + y - 12 = 0 and also their center lies in the line too.
Now, their center is given by :

Also, product of slope will be -1 .( Since, they are parallel )

x = 2y - 1
So, 
Also, C satisfy given line :

Also,

Therefore, the symmetric points is
.
Answer:
Well everyone does
Step-by-step explanation:
The slope is -2:) hope this helped!!