Investigate the shapes made when rectangles are cut on the diagonal
I can describe the shapes made when rectangles are cut on the diagonal.
Investigate the shapes made when rectangles are cut on the diagonal
I can describe the shapes made when rectangles are cut on the diagonal.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- An angle can be exactly a right angle.
- An angle can be less than or greater than a right angle.
- When you cut a square using two diagonal lines, you get four identical triangles.
- When you cut a rectangle that is not a square using two diagonal lines, you get two pairs of identical triangles.
Keywords
Diagonal - A straight line connecting one vertex to another, but is not the side or edge.
Common misconception
Pupils may find it hard to recognise when an angle is greater than a right angle.
You can model this by trying to move the obtuse angle (though pupils don't need to know the term yet) within a right angle checker. They should be able to see that it is too large to fit.
To help you plan your year 3 maths lesson on: Investigate the shapes made when rectangles are cut on the diagonal, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 3 maths lesson on: Investigate the shapes made when rectangles are cut on the diagonal, 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 2 maths lessons from the Right angles unit, dive into the full secondary maths curriculum, or learn more about lesson planning.
Licence
Starter quiz
6 Questions



A four-sided polygon with 4 right angles.
Any four-sided polygon.
A four-sided polygon with 4 right angles and 4 equal sides.

diagonal
vertical
horizontal

Exit quiz
6 Questions




