D-24Non-Verbal ReasoningMon 17 Aug

Rotation vs reflection

Flip and turn are not the same move.

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In non-verbal reasoning, rotate means turn a shape around a point, and reflect means flip it over a mirror line. The options often look almost the same — one is the right transform, the others are the wrong kind of move.

Picture it: turn vs flip

ROTATE = turnAround a point · stays the same shapeREFLECT = flipmirrorOver a line · left↔right or up↔down
  • Rotate — every point swings the same angle around the centre
  • Reflect — every point lands as far the other side of the mirror as it started
  • Same outline can hide both tricks — check which transform the question asked for

Remember — the method

  1. Mark a clear feature (dot, thick edge, shaded corner) on the original.
  2. For a turn: imagine the whole shape spinning 90° or 180° — that feature moves with it.
  3. For a flip: draw the mirror, then ask what lands on the other side.
  4. Reject any option that used the other transform, even if it “looks similar”.

Common turns & mirrors

Rotation amounts

90° = quarter turn · 180° = half turn · 270° = three-quarters

Clockwise vs anti-clockwise matters — read the question.

Mirror lines

Vertical = left↔right flip · Horizontal = top↔bottom flip

Diagonal mirrors appear too — still “flip”, not “spin”.

Exam trap

Options that are a reflection when the question asked for a rotation (or the other way round). They look “nearly right” because the outline is familiar — but a marked corner ends up in the wrong place.

✓ Rotate 90° clockwise

✗ Same shape, but reflected

Question patterns you might see

Same skill, harder outfits — from a clear quarter-turn to mixed transform traps.

  1. 1 · Simple — Quarter turn clockwise

    “Which shows the arrow after a 90° turn clockwise?” Track the tip — it should move a quarter of the way round the centre.

    Start90° clockwise
  2. 2 · Simple — Vertical mirror

    “Reflect in the vertical line.” Left and right swap; top and bottom stay put. The dot that was on the right of the stem moves to the left.

    vertical mirrorOriginalReflection
  3. 3 · Simple — Shaded circles, 90° anticlockwise

    “Some of the circles have been shaded. Which option shows the grid after a 90° anticlockwise turn?” Track one shaded circle around the centre — the whole pattern turns as one block.

    90° anticlockwiseABCDE

    Expl. Every shaded circle swings 90° anticlockwise about the centre — each filled cell moves with the whole pattern. C is correct; traps are clockwise, a mirror, 180°, or the original.

  4. 4 · Simple — Shaded squares, 90° anticlockwise

    Same rule on a filled-square grid (the “checkbox” look). Pick the option after 90° anticlockwise — ignore options that only flip or turn the other way.

    90° anticlockwiseABCDE

    Expl. Every shaded square swings 90° anticlockwise about the centre. Trap answers flip the grid (mirror), turn it the other way, turn it 180°, or leave it unturned — E is correct here.

  5. 5 · Medium — Half turn (180°)

    A 180° rotation puts every point opposite the centre. It can look like a flip at a glance — check a one-sided mark: after 180°, it is upside-down and swapped sides.

    180°Tip that pointed right now points left — and the shape is inverted
  6. 6 · Medium — Circles: 180° vs flip

    Question asks for a half turn. A is 180°; B is a vertical mirror. After 180°, a shaded circle moves opposite the centre (top↔bottom and left↔right); a flip only swaps left↔right.

    OriginalA · 180° ✓B · flip ✗A inverts the whole pattern · B is only a mirror
  7. 7 · Medium — Horizontal mirror

    “Reflect in the horizontal line.” Top and bottom swap; left and right stay. Easy to mix with a vertical flip if you rush.

    horizontal mirrorAbove → belowDot stays on the same sideof the stem (left/right)
  8. 8 · Trickier — Squares: rotate vs reflect

    Question asks for 90° anticlockwise. A is the correct turn; B is a vertical mirror that can look similar at a glance — check where a corner square lands.

    OriginalA · 90° ACW ✓B · reflect ✗A keeps handedness of the turn · B is a mirror image
  9. 9 · Trickier — Same-looking wrong transform

    Question asks for a rotation. One option is the correct turn; another is a reflection that looks almost identical for this shape. Track the marked corner.

    OriginalA · rotate 90°B · reflect ✗A keeps handedness of the turn · B is a mirror image
  10. 10 · Trickier — Clockwise vs anti-clockwise

    Both options are 90° turns — but one goes the wrong way. Read “clockwise” / “anti-clockwise” before you pick.

    StartClockwise ✓Anti-clockwise ✗Same angle, opposite direction — different answer
  11. 11 · Trickiest — Two steps, one rule each

    “Rotate 90° clockwise, then reflect in a vertical mirror.” Do the moves in order. Doing the flip first (or only one step) lands on a popular wrong option.

    1 · Start2 · Rotate 90°3 · ReflectFinish both steps — stop after step 2 and you pick a trap

Coach tip: before choosing, say the rule out loud — “turn” or “flip” — then check one marked corner. If that corner is wrong, the whole option is wrong.

Tomorrow (D-23): “Of” means multiply — fractions of amounts.

Next step

Practice locks the idea in. WhatsApp delivers tomorrow’s tip to your phone — same group as mock updates.