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      Checking understanding of basic transformations

      Lesson details

      Learning outcome

      I can describe how an object has moved or changed.

      Key learning points

      1. A congruent shape has not changed size
      2. Two shapes can be congruent even if one has been reflected or rotated
      3. An image can be described in terms of its object
      4. The description states how the object has been changed

      Keywords

      • Object - The object is the starting figure before a transformation has been applied.

      • Image - The image is the resulting figure after a transformation has been applied.

      • Transformation - A transformation is a process that may change the size, orientation or position of a shape.

      • Congruent - If one shape can fit exactly on top of another using rotation, reflection or translation, then the shapes are congruent.

      • Invariant - A property of a shape is invariant if that property has not changed after the shape is transformed.

      Common misconception

      Students may believe two shapes are congruent based purely on the shape and not the size as well.

      Consider squares - all squares have the same angles and are visually identical but if the lengths are different they're not congruent.

      Teacher tip

      Students could describe verbally to each other. Using MWBs, students could make a description and the other student would need to draw the image based upon the description.

      Licence

      This content is © Oak National Academy Limited (2025), licensed on Open Government Licence version 3.0
      except where otherwise stated. See Oak's terms & conditions
      (Collection 2).

      Lesson video

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      Prior knowledge starter quiz

      6 Questions

      Q1.
      Which is bigger: 4.2 cm or 4 cm?

      Correct answer: 4.2 cm
      4 cm

      Q2.
      In this triangle, the largest interior angle is located at which vertex?

      An image in a quiz
      A
      Correct answer: B
      C

      Q3.
      A half turn means __________ $$^{\circ}$$

      $${90^{\circ}}$$
      Correct answer: $${180^{\circ}}$$
      $${270^{\circ}}$$

      Q4.
      Match the edges to the correct lengths.

      An image in a quiz
      Correct Answer:QP,4.9 cm
      Correct Answer:PS,5.4 cm
      Correct Answer:RQ,3.3 cm
      Correct Answer:SR,5.8 cm

      Q5.
      Select all the quadrilaterals.

      Correct answer: square
      Correct answer: rectangle
      pentagon
      triangle
      Correct answer: trapezium

      Q6.
      The vertices in the quadrilateral PQRS has been labelled in the direction.

      An image in a quiz
      Correct Answer: anticlockwise, anti-clockwise

      6 Questions

      Q1.
      A transformation is a process that may change the size, orientation or of a shape.

      Correct Answer: position

      Q2.
      This L shape is flipped over once, which of these could be the image?

      An image in a quiz
      Correct Answer: An image in a quiz
      An image in a quiz
      Correct Answer: An image in a quiz
      An image in a quiz
      An image in a quiz

      Q3.
      The quadrilateral ABCD is transformed. How should the image of vertex A be labelled?

      Correct Answer: A', A dash, A prime, A`

      Q4.
      Which of these show a pair of congruent shapes?

      An image in a quiz
      Correct Answer: An image in a quiz
      An image in a quiz
      An image in a quiz

      Q5.
      Regardless of whether an object is flipped, twisted or moved which properties are invariant?

      Correct answer: angles
      Correct answer: lengths
      orientation
      position
      mirrored

      Q6.
      Which figure does this description match: The object has been twisted half a turn.

      An image in a quiz
      An image in a quiz
      Correct Answer: An image in a quiz
      An image in a quiz

      To help you plan your 7 maths lesson on: Checking understanding of basic transformations, download all teaching resources for free and adapt to suit your pupils' needs...