Similarity in shapes
I can recognise that similar shapes have sides in proportion to each other but angle sizes are preserved.
Similarity in shapes
I can recognise that similar shapes have sides in proportion to each other but angle sizes are preserved.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- Two shapes are not similar if there is a pair of lengths with a different multiplicative relationship.
- Similar shapes are not always easy to spot visually.
- A ratio table can help you find the scalar and functional multipliers in similar shapes.
- The angle sizes do not change.
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.
Similar - Two shapes are similar if the only difference between them is their size. Their side lengths are in the same proportions.
Common misconception
Pupils may find it difficult to match up corresponding measurements on two congruent shapes when they are in different orientations.
Look lengths which are between any pairs of known angles or look for angles which are between pairs of adjacent known lengths. Also, tracing paper could be used to reflect/rotate/translate one shape onto the other.
To help you plan your year 9 maths lesson on: Similarity in shapes, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 9 maths lesson on: Similarity in shapes, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 3 maths lessons from the Geometrical properties: similarity and Pythagoras' theorem unit, dive into the full secondary maths curriculum, or learn more about lesson planning.
Licence
Lesson video
Starter quiz
6 Questions
Exit quiz
6 Questions
