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
.
Rajid it is (e) 3/4 and please follow me I need a follower
Answer:
b = 12.6
Step-by-step explanation:
a*2 + b*2 = c*2
6*2 + b*2 = 14*2
36 + b*2 = 196
Subtract 36 from both sides
36 + b*2 = 196
-36 -36
b*2 = 160
Find the square root of both
b = 12.64911064 or 12.6
I dont know maybe I just want points
2