In this problem, they want you to take the triangle and flip it over the line. It's going to create a mirror image on the other side.
That line is y = x, which is just a basic plain diagonal line that goes bottom left to top right.
To start, I would ALWAYS write down the coordinates of the original triangle.
D (-1, 3)
F (-3, 1)
E (-1, 1)
Now, <em>here's the trick</em>
Anytime it asks you to flip over Y = X, <em>remember</em> that you just flip X and Y!!!
(X, Y) --> (Y, X)
Your new coordinate points are going to be:
D (3, -1)
F (1, -3)
E (1, -1)
Now, just plot those points, connect the dots, and you have your new, mirrored triangle!
