Mirror & Water Images
🔒 Log in to trackWater images (horizontal mirror)
🔒 Log in to trackWater below an object works as a horizontal mirror. It swaps top and bottom and keeps left and right. In a water image the order of the characters stays the same, and every character is turned upside down. Letters with a horizontal line of symmetry look unchanged.
What water does
A lake below a hill shows the hill upside down. The water surface is a horizontal mirror below the object.
It swaps top and bottom. It keeps left and right. A question may say "the mirror is placed horizontally below" or "along line MN below the figure". All of these mean a water image.
For a word, number or code:
- The order stays the same. The first character is still first.
- Each character is flipped top to bottom.
Rule: Water image = keep the order + flip every character top to bottom.
Letters that look the same
Capitals with a horizontal line of symmetry look the same in water.
B C D E H I K O X, and the digits 0, 3 and 8.
A word looks the same in water if every letter is in this list. It does not need to be a palindrome, because water keeps the order.
Examples: CHOICE, BOX, HIDE, CODE, DECIDE.
Watch: A, M, T, U, V, W and Y are symmetric in a mirror but not in water. M upside down looks like W.
Four-step check for options
- The first character stays first. An option that starts with the last character is a mirror image or a half turn.
- Check one letter that is not in the list, such as A, R, T, 4 or 7. It must be upside down.
- Parts that faced left must still face left. The bowl of R stays on the right side.
- Compare the rest only if two options are left.
Mirror plus water is a half turn
A mirror image followed by a water image, in either order, is a half turn (180 degrees). The order is reversed and every character is upside down.
After a half turn, H, I, N, O, S, X, Z, 0 and 8 look unchanged. So SOS, NOON and XOX look the same after a half turn.
Figures
Every point moves to the same distance on the other side of the horizontal line. Top goes to bottom. Left and right do not change.
- Top-left goes to bottom-left in a water image.
- Top-right would be a mirror image.
- Bottom-right would be a half turn.
Tip: Track one feature, such as a shaded corner. It tells you the image type at once.
Naming the image
Look at two things: is the order reversed, and is anything upside down?
| Order | Letters | Image |
|---|---|---|
| Reversed | Flipped left to right | Mirror image |
| Same | Upside down | Water image |
| Reversed | Upside down | Half turn |
Numbers in water
Digits follow the same rule. Keep the order and flip each digit top to bottom.
0, 3 and 8 look unchanged. In 83602, the digits 8, 3 and 0 look the same, while 6 and 2 look different.
Worked example
Water image of BUDGET.
The order stays B U D G E T. B, D and E look unchanged. U, G and T appear upside down. An option that begins with T is not a water image.
Question types you will see
Each type: how to recognise it, the method step by step, and one question to try.
Water image of a word
A word in capitals with a horizontal mirror below it.
Keep the order.
Turn each letter upside down. B, C, D, E, H, I, K, O, X look unchanged.
Left-facing parts stay on the left.
A horizontal mirror only swaps top and bottom.
Which describes the water image of BUDGET?
Show solutionHide solution
The order stays B, U, D, G, E, T.
B, D and E have a horizontal line of symmetry, so they look unchanged.
U, G and T appear upside down.
B U D G E T, with U, G and T upside down and B, D, E unchanged
Water image of a number or code
A number or a letter-digit code with water image options.
Keep the order.
Turn each character upside down. 0, 3 and 8 look unchanged.
Do not treat 6 as 9.
Water is a flip, not a spin.
Which digits of 83602 look unchanged in water?
Show solutionHide solution
8, 3 and 0 have a horizontal line of symmetry.
6 and 2 look different upside down.
8, 3 and 0
Water image of a figure
A line figure with a horizontal line MN below it.
Pick a clear feature.
Move it to the other side of the horizontal line. Keep its left-right position.
Reject options where it moved sideways.
Water keeps left and right.
A figure has a shaded triangle in its top-right corner. Where is the triangle in the water image?
Show solutionHide solution
Top and bottom swap.
Left and right stay the same.
Bottom-right corner
Words unchanged in water
Which word looks the same in water.
Tick the letters from B C D E H I K O X.
A word looks the same only if every letter is ticked.
These letters have a horizontal line of symmetry.
Which word looks the same in water: CHOICE or CHANCE?
Show solutionHide solution
Every letter of CHOICE is in B C D E H I K O X.
CHANCE has A and N, which are not.
CHOICE
Mirror image followed by water image
A word is seen in a mirror and then in water, or the other way round.
Mirror then water is a half turn.
Reverse the order.
Turn every character upside down.
Swapping left and right, then top and bottom, is a half turn.
How does the word SUN look after a mirror image followed by a water image?
Show solutionHide solution
Half turn: the order reverses to N, U, S.
N and S look the same after a half turn.
U looks like a cap, an upside-down U.
N U S, with U upside down and N, S unchanged
Count letters unchanged in water
How many letters of a word look the same in water.
Tick the letters from B C D E H I K O X.
Count every tick, including repeats.
Each ticked letter has a horizontal line of symmetry.
How many letters of DIRECTION look the same in water?
Show solutionHide solution
D, I, E, C, I, O are in the list.
R, T and N are not.
6
Name the image type
A word and its image are described. The question asks which kind of image it is.
Is the order reversed?
Are letters flipped left to right, or upside down?
Use the table: reversed and flipped means mirror, same order and upside down means water, reversed and upside down means half turn.
Each kind of image changes the order and the flips in its own way.
The word FLAG appears as G A L F, with every letter facing the other way and none upside down. Which image is this?
Show solutionHide solution
The order is reversed.
Letters are flipped left to right.
Nothing is upside down.
A mirror image
Shortcuts that save time
In the options, look for the one that keeps the original order and has only the unsymmetric letters turned upside down.
What is the water image of BOX?
Show solutionHide solution
B, O and X are all symmetric top to bottom.
Water keeps the order.
BOX, unchanged
Same order and upside down: water. Reversed order and flipped left to right: mirror. Reversed and upside down: half turn.
A word appears with its order reversed and every letter upside down. What is this image?
Show solutionHide solution
The order is reversed, so it is not water.
Letters are also upside down, so it is not a mirror image.
A half turn (mirror plus water)
Mistakes to avoid
Where most students lose marks on this subtopic.
Reversing the order of the characters in a water image.
Water keeps the order. Only top and bottom swap.
Spinning letters through a half turn instead of flipping them top to bottom.
A water image is a flip. Left-facing parts still face left.
Using the mirror list A H I M O T U V W X Y for water.
Water list: B C D E H I K O X.
Thinking 6 upside down becomes 9 in water.
9 is a half turn of 6. A water image flips top to bottom only.
Calling a reversed, upside-down word a mirror image.
Reversed order plus upside down is a half turn.
Quick revision
Read this the night before the exam.
Water image: keep the order and flip every character top to bottom.
Symmetric in water: B C D E H I K O X, and digits 0, 3, 8.
Same word in water: every letter must be in that list.
Mirror plus water is a half turn: reversed order and upside down.
Figures: top and bottom swap. Left and right stay.
Same order and upside down: water. Reversed and flipped: mirror.
Practice: 18 questions
Sets of 10, mixed across the question types above. Every answer has a step-by-step explanation.
Topic test · 10 questions
Suggested time 7 min · wrong answers go to your mistake notebook automatically.