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A reflection across the line y=0 (AKA the x-axis)
and then across the line x=0 (AKA the y-axis)
is the same as a rotation of 180º
clockwise about the origin because the lines intersect at the origin and at a 90º angle.
While all of that is true, you could also be more general, because reflecting over any two lines that intersect at the origin will result in a rotation about the origin and have an angle of rotation equal to twice that of the acute angle formed between the intersecting lines.