The figure reflected across any vertical or horizontal line will not fold completely over itself. If rotated 90° either way (clockwise or anticlockwise) it would still not cover itself completely. But if rotated 180° either way (clockwise or anticlockwise), then it would cover itself completely and congruently.
$8.40 is the amount to be subtracted from the $42.00. If you multiply 20% (.20) by $42.00 you get $8.40. To get your final price subtract $8.40 from $42.00 to get you final answer. I hope that helps.
