You should know that you can predict changes in coordinates after translations without a graph or anything like that.
(x, y) reflected over the x axis = (x, -y) (x, y) reflected over the y axis = (-x, y) (x, y) rotated 90 degrees around the origin = (y, -x) (x, y) rotated 180 degrees around the origin = (-x, -y) (x, y) rotated 270 degrees around the origin - (-x, y)
So here's our set of points. A(1, 2), B(4, 6), C(4, 6)
Here's those points reflected over the x axis. A'(1, -2), B'(4, -6), C'(4, -6)
And here's <em>those</em> points rotated 180° around the origin. A''(2, -1), B''(6, -4), C''(6, -4)
I think you made a mistake writing down the question, though, because B and C are the same yet you say ABC forms a triangle. You should be able to go through this process with whatever the coordinate was supposed to be.