Bisecting an angle
I can use the properties of a rhombus to construct an angle bisector.
Bisecting an angle
I can use the properties of a rhombus to construct an angle bisector.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- A rhombus can be constructed from two congruent isosceles triangles.
- The diagonals of a rhombus bisect the angles.
- It is possible to construct an angle bisector without drawing the rhombus.
Keywords
Bisect - To bisect means to cut or divide an object into two equal parts.
Rhombus - A rhombus is a parallelogram where all sides are the same length.
Congruent - If one shape can fit exactly on top of another using rotation, reflection or translation, then the shapes are congruent.
Common misconception
I can use a protractor to measure an angle, then half that angle to bisect it.
Constructions, such as bisecting an angle, are methods of creating & modifying shapes & angles in ways that don't require measurement tools.
To help you plan your year 8 maths lesson on: Bisecting an angle, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 8 maths lesson on: Bisecting an angle, 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
Lesson video
Starter quiz
6 Questions
118°
31°
59°
90°
Exit quiz
6 Questions
