A piece of paper is folded along the dotted line successively along the directions shown and is then punched in the last. How would the paper look when unfolded?
- A[Top row: ; Middle row: Vertical rectangle flanked by two circles; Bottom row: ]
- B[Top row: ; Bottom row: (Identical shapes directly mirrored vertically)]
- C[Top row: ; Middle row: Single vertical rectangle; Bottom row: ]
- D[Top row: ; Bottom row: Triangles pointing outwards with no lower rectangle]
Solution & Step-by-step Explanation
When the paper is unfolded from top to bottom along the horizontal crease line:
4. The shapes punched in the top half will create a vertical mirror image directly in the bottom half.
5. For a vertical mirror reflection (top-to-bottom unfolding):
* The top and bottom orientations invert if asymmetrical vertically, but left and right orientations remain completely unchanged.
* Therefore, the right-pointing triangle () remains right-pointing ().
* The central vertical rectangle () remains a vertical rectangle ().
* The left-pointing triangle () remains left-pointing ().
Thus, the unfolded paper will show two identical horizontal rows of shapes: on the top half and on the bottom half. This matches Option B.
4. The shapes punched in the top half will create a vertical mirror image directly in the bottom half.
5. For a vertical mirror reflection (top-to-bottom unfolding):
* The top and bottom orientations invert if asymmetrical vertically, but left and right orientations remain completely unchanged.
* Therefore, the right-pointing triangle () remains right-pointing ().
* The central vertical rectangle () remains a vertical rectangle ().
* The left-pointing triangle () remains left-pointing ().
Thus, the unfolded paper will show two identical horizontal rows of shapes: on the top half and on the bottom half. This matches Option B.