"what set of reflections would carry hexagon abcdef onto itself? .
hexagon abcdef on the coordinate plane with point
a at negative 1, 1, point
b at negative 3, 1, point
c at negative 4, 2, point
d at negative 3, 3, point
e at negative 1, 3, and point
f at 0, 2. .
x-axis, y=x, x-axis, y=x .
. y=x, x-axis, y=x, y-axis .
. y-axis, x-axis, y-axis .
. x-axis, y-axis, y-axis ."