To make a transformation by reflection over the line y = -x, we switch our x and y, and make both negative.
[tex](X,\text{ Y) }\rightarrow\text{ }(-Y,\text{ -X)}[/tex]
Since the given figure was already transformed one, we get,
A' = (-Y, - X) = (1,2)
B' = (-Y, - X) = (1,1)
C' = (-Y, - X) = (2,1)
D' = (-Y, - X) = (2,3)
To make the original figure before the transformation, let's convert the transformed coordinates into the original form.
A = (X, Y) = (-2, -1)
B = (X, Y) = (-1, -1)
C = (X, Y) = (-1, -2)
D = (X, Y) = (-3. -2)
Let's now plot the original one,
