Area of a triangle
I can derive the formula for the area of a triangle.
Area of a triangle
I can derive the formula for the area of a triangle.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- It is possible to find a relationship between triangles and parallelograms.
- You can use this relationship to find a formula for the area of a triangle.
- It is possible to identify the base and perpendicular height of any triangle even when they are not obvious.
- The formula can be used to find the area of any triangle.
Keywords
Base - The base is the side which is perpendicular to the height.
Perpendicular height - The perpendicular height is the perpendicular distance from the base to the opposite vertex.
Common misconception
Pupils may forget to halve after multiplying the base and the perpendicular height.
The area of a triangle is equal to half the area of the parallelogram formed by two of those triangles.
To help you plan your year 7 maths lesson on: Area of a triangle, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 7 maths lesson on: Area of a triangle, 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 Perimeter and area unit, dive into the full secondary maths curriculum, or learn more about lesson planning.
Licence
Starter quiz
6 Questions




Exit quiz
6 Questions


