Angles in triangles
I know that the angles in a triangle sum to 180°.
Angles in triangles
I know that the angles in a triangle sum to 180°.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- Angles on a straight line sum to 180 degrees.
- Interior angles in triangles sum to 180 degrees.
- Missing angles can be calculated using the sum of 180 degrees.
Keywords
Quadrilateral - A quadrilateral is a polygon with four straight sides and four vertices.
Triangle - A triangle is a polygon with three straight sides and three vertices.
Sum - The sum is the result of adding two or more numbers.
Common misconception
Pupils struggle to remember the number of degrees in a triangle as they only know it as a disconnected fact.
Apply pupils' knowledge of angles in a quadrilateral to understanding the sum of the angles in a triangle. Spend time showing how a quadrilateral is constructed using triangles and what happens to the angles as the quadrilateral is partitioned.
To help you plan your year 5 maths lesson on: Angles in triangles, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 5 maths lesson on: Angles in triangles, 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 Angles: compare, name, estimate and measure angles unit, dive into the full secondary maths curriculum, or learn more about lesson planning.
Licence
Starter quiz
6 Questions



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Exit quiz
6 Questions

