Part B Enter the numerical coordinates of the vertices of quadrilateral ABCD in the table. (Point A has been done for you.) Then predict the numerical
coordinates of the vertices of quadrilateral A'B'C'D' as the figure reflects about four different lines of reflection: x-axis, y-axis, y = x, and y = -x.

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

i would need to see the dot plot : )

if you was gonna solve for a, a is a   < -12