Identify the result of one reflection in a stated mirror line.
Free to use and free to share. There is no sign-up, no score, and nothing a child does here is recorded or sent anywhere.
Practise it now
Which shape is the target reflected in the mirror line? Tap one and watch the ghost flip across.
This exercise practises reflect a shape alongside its own main skill, Reflection.
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A worked example
One question of the kind this skill is tested with, worked all the way through: the reasoning, and what the wrong answers are there to catch.
Reflecting a shape in a named mirror line
Watch where each corner lands when you reflect in the horizontal mirror line.
Every point of the shape ends up the same distance from the horizontal mirror line as it started, but on the other side of it.
flipped, then turned 180° clockwise
flipped, then turned 90° clockwise
turned 180° clockwise
flipped, with no turn
Answer: flipped, then turned 180° clockwise
How you get there
Reflecting in the horizontal mirror line keeps every point the same distance from that line and puts it on the opposite side, so a shape flipped in any other line lands somewhere else and a turned shape stays the same way round.
Why the other answers tempt
Several options are flipped - only one of them is flipped in the line the question names.
If they are stuck, say this
Pick the corner furthest from the horizontal mirror line and check it lands the same distance away on the other side.
Which shape is the target reflected in the mirror line? Tap one and watch the ghost flip across.
This engine’s own main skill is Reflection. It practises reflect a shape alongside it.
A reflection in a vertical mirror swaps left and right and leaves top and bottom exactly as they were. That single rule kills every trap here. A rotation turns the shape round, so its top and bottom swap too. A translation slides the shape without changing which way it faces, so anything sticking out to the right still sticks out to the right. A flip in a horizontal mirror changes top and bottom instead of left and right. The safe method in the exam is to pick one distinctive corner, work out where the mirror sends it, and check the candidates against that single point before comparing the whole shape.
What to say if they get stuck
A reflection swaps left and right but never turns the shape upside down.
Pick one corner of the target, such as the step near the top, and ask which side of the shape it should end up on after the flip.
Three of these are traps: one has been turned right round, one has simply slid sideways without flipping, and one has been flipped top to bottom instead of left to right.
Exactly one of these readings comes out different. Which one?
This engine’s own main skill is What Stays the Same When a Shape Moves. It practises reflect a shape alongside it.
The programme is “Slide 4 right”, then “Slide 2 right”, then “Flip in the line x = 4”. Every move on that list picks the outline up and puts it down without changing its size or shape, so the lengths of the sides, the angles at the corners and the area inside are all exactly what they were. What a rigid motion does change is WHERE things are, and here that is the coordinates of corner A. There is one more thing a flip changes and a slide or a turn never does: the letters ran anticlockwise round the outline and now run clockwise. The exam-safe habit is to sort every reading into "about the shape itself" or "about where the shape is": the first kind always survives, the second kind is the only place an answer can hide.
Step 1. Watch it move. Play the cards and watch the readings.
Step 2. The odd one out. Which single reading came out different?
What to say if they get stuck
Tap a reading and it is drawn twice: once on the faint outline where the shape started, once on the solid one where it is now. Scrub slowly and watch whether the two marks stay the same.
A slide, a turn and a flip all pick the outline up without stretching or squashing it, so every length, every angle and the area come through untouched.
A flip is the only one of the three that reverses the outline, and this programme has one of them, so the letters end up reading round the other way.
The move has already happened. Play each card on the outline and find the one that lands on the ghost exactly.
This engine’s own main skill is Identifying Transformations. It practises reflect a shape alongside it.
The move was “Turn 90° anticlockwise about (-4, 2)”. The card beside it, “Turn 90° clockwise about (4, 3)”, is the same kind of move, so calling it a turn settles nothing: what has to be read is which way round it turns, and which point it turns about. It comes down to one corner. A starts at (-1, -3) and the ghost has it at (1, 5); the other card sends it to (-2, 8) instead. That card does get one corner exactly right, which is why one corner is never enough on its own. That is the exam-safe method: settle what is different about the two cards, then pin it down with a single corner.
Step 1. Look at it. Drag the track to play a card and watch where the outline goes. Scrub back to try another.
Step 2. Name the move. Which card was played? Pick the one that lands the outline exactly on the ghost.
What to say if they get stuck
Both cards play the same kind of move, so deciding it was a turn does not choose between them. What is different is which way round it turns, and which point it turns about.
Follow one corner. A starts at (-1, -3) and the ghost has it at (1, 5), so the right card has to send it exactly there.
Check a second corner before you lock in. The wrong card here lands one corner exactly where the ghost has it and every other corner somewhere else.
The 11+ does not test these skills in isolation, and practising one in the wrong order wastes the practice. These are the skills the curriculum map connects this one to.
A geometric reflection can transfer to provider-style marked-figure reasoning.
How reflect a shape differs from the skills beside it
The same exercise practises several skills, and telling them apart is often the difficulty rather than the exercise itself. On this page the skill is: identify the result of one reflection in a stated mirror line, and it stops where excludes rotation and translation.
Identify the translation, rotation, or reflection relating a shape and its image. Identifies the transformation from supplied figures or coordinates. It does not execute the transformation.
Use the fact that translation, rotation, and reflection preserve lengths and angles. Excludes calculating an unknown measure from unrelated angle or length rules.
Answered from what the skill map records about this skill, not from a template. Every answer here is on the page, and the same questions are the page's FAQ structured data.
Identify the result of one reflection in a stated mirror line. It is one of 55 named maths skills in the 11+, in the geometry strand, and this page carries 3 interactive exercises that practise it.
Several options are flipped - only one of them is flipped in the line the question names. The wrong answers on this skill are built out of that, not out of random numbers, so it is worth naming out loud before your child meets it under time pressure.
No. To reflect a shape is to identify the result of one reflection in a stated mirror line. To rotate a shape is to identify the result of one stated rotation. Rotation and reflection are commonly confounded. Telling the two apart is often the real difficulty in the question.
Point at the next move rather than explaining the whole rule. Pick the corner furthest from the horizontal mirror line and check it lands the same distance away on the other side.
The skill map draws the line here: Excludes rotation and translation. A question past that line is testing a different named maths skill, which is worth knowing before you spend a week practising the wrong one.
The skill map connects it to reflect a visual figure. A geometric reflection can transfer to provider-style marked-figure reasoning. That skill has its own page here.
Use Through the Mirror, Spot the Changed Reading and Which Card Was Played?, embedded on this page. They are the exercises the skill map attaches to reflect a shape, they run in the browser with no account to make, nothing is scored, and nothing a child does here is recorded or sent anywhere. Each also has its own link, so you can send one to a child without sending them anywhere else first.
Is it reflect a shape they find hard, or telling it apart from rotate a shape?
Those two look like one weakness on a practice paper and need completely different practice. A free diagnostic tells them apart across all four subjects.
