Module 16 of 30Lesson 1 of 2 · TV-F1 Slides, Flips and Turns
Transformations & Vectors strand · Unit TV-F1 · Builds towards C7.1

Slides, Flips & Turns

🟢 Foundation levelShapes on the move

1 Learn it
🔑 Four ways a shape can move: TRANSLATION — a slide (same size, same orientation, new place) · REFLECTION — a flip over a mirror line · ROTATION — a turn about a fixed point · ENLARGEMENT — a resize from a centre. The first three keep the shape CONGRUENT (identical size); enlargement changes size but keeps it SIMILAR (G-C6!).

Object → image: the original shape is the OBJECT; the moved copy is the IMAGE (often labelled A′). Corresponding points hop consistently: if one vertex moves 3 right and 2 up in a translation, every vertex does.

Spotting game: image flipped over? Reflection. Same way up, new spot? Translation. Turned? Rotation. Bigger/smaller? Enlargement.

2 Watch it work
EXAMPLE 1

A triangle moves 4 squares right and 1 up, staying the same way round. Which transformation?

Translation — the pure slide.

EXAMPLE 2

A shape and its image are mirror twins across a vertical line. Which transformation?

Reflection — each point and its twin sit at equal distances from the mirror.

EXAMPLE 3

An L-shape appears upside-down on the other side of a point. Which transformation?

Rotation of 180° about that point.

EXAMPLE 4

Which of the four transformations does NOT produce a congruent image?

Enlargement — size changes; only the SHAPE survives.

3 Your turn — try first, then reveal
🚫 No calculator[1 mark]

Q1. Name the transformation that slides a shape without turning or flipping it.

👀 Show answer
✍️ How your working should look in the exam
translation   ✓ B1
Why this works
Every point makes the identical hop.

🚫 No calculator[1 mark]

Q2. After a reflection, how do the distances of a point and its image from the mirror line compare?

👀 Show answer
✍️ How your working should look in the exam
equal   ✓ B1
Why this works
Mirror twins, same distance either side.

🚫 No calculator[1 mark]

Q3. Which transformations keep the image congruent to the object?

👀 Show answer
✍️ How your working should look in the exam
translation, reflection and rotation   ✓ B1
Why this works
Size and shape preserved; only enlargement resizes.

🚫 No calculator[1 mark]

Q4. A photo is printed at half size. Which transformation relates print to original, and are they congruent or similar?

👀 Show answer
✍️ How your working should look in the exam
enlargement (scale factor ½) — similar   ✓ B1
Why this works
“Enlargement” covers shrinking too — fractional scale factors shrink.

🚫 No calculator[1 mark]

Q5. A shape is turned to face the opposite direction about a point. What rotation is this?

👀 Show answer
✍️ How your working should look in the exam
180°   ✓ B1
Why this works
Half a turn — no direction needed at 180°.

4 Common mistakes — don’t lose easy marks
  • “Enlargement” assumed to mean bigger only: fractional scale factors shrink.
  • Rotation confused with reflection: reflections flip the lettering order; rotations keep it.
  • Object and image labels swapped: the dash (A′) marks the IMAGE.
  • Freehand images: ruler for every straight edge — the syllabus says so.
5 Where this leads

Core units make each move precise: mirror-line equations, rotation centres, column vectors and scale factors — and teach the FULL DESCRIPTION each transformation demands.

✅ Take the Check Yourself quiz below, then continue to TV-C1 Reflection and Rotation.

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