11+ Non-verbal reasoning · Topic explained
Reflection
What would this shape look like in a mirror?
The big idea
A reflection flips a shape across a mirror line. Every point lands the same distance away on the other side.
Picture it
Wave your right hand at a mirror: your reflection waves back from the other side.
Key words
- mirror line
- the line the shape flips over
- reflection
- the flipped copy
- same distance
- close to the line stays close, far stays far
Worked examples
- 1Warm-up
Reflect the arrow in the upright mirror line.
- It points towards the mirror…
- …so its reflection points back: left.
- 211+ standard
Reflect the picture in the upright mirror line. Which is right?
- Left and right swap; top and bottom stay put.
- The half turn is a trap: it moves the dot to the bottom.
- 311+ standard
Reflect the L-shape in the flat mirror line.
- A flat mirror line flips top and bottom.
- The foot moves from the bottom to the top.
- 411+ standard
Reflect the dot in the upright mirror line.
- The dot is close to the mirror line.
- So its reflection is just as close, on the other side.
The common mistake
The mistake
A reflection is the same as a half turn.
Instead
A flip and a turn are different; check which way the shape faces and where each part ends up.
Why: For many shapes a half turn and a reflection look similar, so GL uses one as a trap for the other.
Where it comes up in the 11+
GL papers ask for reflections in upright and flat mirror lines, and use them as traps in rotation questions.
The video
Video coming soon
We're making a short video that explains reflection step by step. Until then, everything it covers is on this page.
Free printable
Reflection worksheet
Practice questions on this topic to print and try on paper, at home or on the way to school.
Download the worksheet (PDF)Free account needed: it takes a minute.
Quick quiz
Have a go first, then tap to see the answer.
1. An arrow points left. Reflect it in an upright mirror line. Where does it point?
- right
- left
- up
- down
Show the answerHide the answer
right
Left and right swap.
2. An arrow points up. Reflect it in a flat mirror line. Where does it point?
- down
- up
- left
- right
Show the answerHide the answer
down
Top and bottom swap.
3. A dot is very close to the mirror line. Where is its reflection?
- very close, on the other side
- far away
- on the line
- in the same place
Show the answerHide the answer
very close, on the other side
Every point stays the same distance from the line.