Concept 1 of 9
Mirror Images: Left-Right Flip
Today's big idea
A mirror swaps left and right, so letters with a vertical line of symmetry survive.
Check which way the symmetry line runs, since the wrong axis flips the letter.
How it works
👀 What's going on?
Hold a word up to a mirror and most of it comes back scrambled, while a few letters look untouched. Which ones survive is not luck at all.
💡 Here's the trick
Look at the mirror above. A mirror swaps left and right and leaves top and bottom exactly as they were. A letter with a vertical line of symmetry lands back on itself, so it appears unchanged.
🪄 How to do it
- 1.Draw a vertical line down the middle of each letter in the mirror above.
- 2.Ask whether the two halves match across that line.
- 3.If they match the letter survives, and if not it flips.
✍️ Try it
Does E change in a mirror? Then: does T?
E is symmetric top to bottom but not left to right, so E does change. T has a vertical line of symmetry, so T looks the same.
⚠️ Watch out
You might be thinking any symmetric-looking letter is safe. Check which way the line runs. E is symmetric the wrong way round, so a mirror flips it while a water image would leave it alone.
🌟 Why this matters
Reading the word on the front of an ambulance in your rear-view mirror is exactly this, which is why it is painted reversed.
Exam tip: Learn the eleven letters with vertical symmetry, since the questions come back to them.
Watch me solve one
Quanta solves it
“Watch how I think through one of these — then you try.”
THE PROBLEM
“Which of F, G, A, K is the SAME in a vertical mirror?”
- 1
Recall symmetric letters
A·H·I·M·O·T·U·V·W·X·Y all have vertical symmetry. 🪞
- 2
Scan the options
F (no), G (no), A (yes), K (no).
- 3
Answer ✓
A
Now you try one — same steps, different story 👇
See it in action
⚡ Time to play!
A vertical mirror swaps LEFT and RIGHT. Reveal the reflection, then name it.
MIRROR · ROUND 1 OF 3
Quick check
✅ VERIFICATION
Which of these letters is CHANGED by a mirror placed to its right?
⚡ Finish the activity above first to answer.
Keep going!
Up next: Water Images
6↔9 flips. 0, 8 unchanged. Imagine a pond.