Area of a circle
I can understand the derivation of the area of a circle.
Area of a circle
I can understand the derivation of the area of a circle.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- A circle can be cut into congruent sectors that are placed together to make a parallelogram.
- The length of the parallelogram is half the circumference of the circle.
- The height of the parallelogram is the radius of the circle.
- The formula for the area of a circle can be derived from the area of this parallelogram.
Keywords
Area - Area is the size of the surface and states the number of unit squares needed to completely cover that surface.
Radius - The radius of a circle is any line segment that joins the centre of a circle to its edge.
Diameter - The diameter of a circle is any line segment that starts and ends on the edge of the circle and passes through the centre.
Common misconception
Pupils may confuse the formula for area with the 2πr version of the formula for circumference.
Area is a 2-dimensional space so its formula requires the multiplication of two lengths. This happens when we square the radius.
To help you plan your year 8 maths lesson on: Area of a circle, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 8 maths lesson on: Area of a circle, 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, area and volume unit, dive into the full secondary maths curriculum, or learn more about lesson planning.
Licence
Starter quiz
6 Questions





Exit quiz
6 Questions






