I need the reflection on this one

Your line is y = -x ,, which goes through quad 2 and quad 4

The rule for this line is:
( x, y ) —> ( -y, -x )

which in your case is:
(2,-5) —> (5,-2)
(2,-8) —> (8,-2)
(-8,-5) —> (5,8)
(-8,-8) —> (8,8)

then plot those new points in the grid and that’s the reflection of your rectangle