posted by rob .
Given ABCD with A = (1,1),B = (4, 2), C = (4, 5), and D = (1, 4),what are the coordinates for Point D' if the y-axis is the reflecting line?
reflect through y-axis takes (x,y) --> (-x,y)
So, D(1,4) --> D'(-1,4)
Don't know why all the nonsense about ABC unless there are other problems relating to the figure.