Diagonals of a rhombus
I can appreciate that the diagonals of a rhombus bisect one another at right angles and the angles are bisected.
Diagonals of a rhombus
I can appreciate that the diagonals of a rhombus bisect one another at right angles and the angles are bisected.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- An isosceles triangle has a line of symmetry that splits it into two congruent triangles.
- In a rhombus each diagonal splits the rhombus into two congruent isosceles triangles bisecting the angles.
- The two diagonals meet at right angles.
- The two diagonals bisect each other.
Keywords
Bisect - To bisect means to cut or divide an object into two equal parts.
Altitude - The altitude of a triangle is a line segment from a vertex of a triangle to the opposite edge. It is perpendicular to that edge.
Common misconception
Pupils may struggle with a diagonal of a shape being vertical or horizontal.
By reminding pupils of the definition, ask them to check if it fits and the shape could be rotated as well.
To help you plan your year 8 maths lesson on: Diagonals of a rhombus, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 8 maths lesson on: Diagonals of a rhombus, 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 Constructions unit, dive into the full secondary maths curriculum, or learn more about lesson planning.
Licence
Starter quiz
6 Questions
Scalene triangle -
74°, 36° and 70°
Isosceles triangle -
28°, 124° and 28°
Right-angled triangle -
30°, 60° and 90°
Equilateral triangle -
60°, 60° and 60°





Exit quiz
6 Questions

