Mirror & Water Images
A mirror image reflects left-right (a vertical mirror): the order of letters reverses and each letter flips horizontally. A water image reflects top-bottom (reflection in water): each character flips vertically. Letters symmetric about the relevant axis look unchanged.
Two different mirrors
The trick is knowing which axis flips. A mirror is a vertical line beside the object → it swaps left and right. A water reflection is a horizontal line below the object → it swaps top and bottom.
Letters that do NOT change in a vertical mirror
Letters symmetric about a vertical axis look the same in a mirror: A, H, I, M, O, T, U, V, W, X, Y. For a word, the mirror also reverses the order of the letters, so "BOX" becomes the reverse with each letter flipped.
✅ Solved examples
✏️ Practice — try these, take hints as needed
📝 Topic test — 8 questions
Auto-graded with full solutions; saved to your dashboard. Use the calculator and formula sheet (top-right) any time.
Formula Reference Sheet
The governing rules
| Mirror image | left ↔ right (vertical mirror) |
|---|---|
| Water image | top ↔ bottom (horizontal/water surface) |
| Dice | opposite faces sum to 7 (standard die) |
| Painted cube (n×n×n) | corners 8, edges 12(n−2), faces 6(n−2)², inner (n−2)³ |
| Paper folding | each fold doubles the punched holes (2^folds) |