Reflect ABC over the y-axis.
A()
B()
C()
.
To reflect a point over the y-axis, we simply change the sign of the x-coordinate. The y-coordinate remains the same.
So, reflecting point A() over the y-axis would result in A'().
Reflecting point B() over the y-axis would result in B'().
Reflecting point C() over the y-axis would result in C'().