Myths about teaching can hold you back
- Year 7
Calculating missing lengths with perimeter of polygons
I can use the properties of a range of polygons and the perimeter of a given polygon to deduce missing side lengths.
- Year 7
Calculating missing lengths with perimeter of polygons
I can use the properties of a range of polygons and the perimeter of a given polygon to deduce missing side lengths.
Lesson details
Key learning points
- Missing side lengths can be found if the perimeter is known.
- Perimeter problems involve a context where the distance around a 2D shape is wanted.
Keywords
Perimeter - The perimeter is the distance around a 2D shape.
Polygon - A polygon is a flat (2D), closed figure made up of straight line segments.
Common misconception
Pupils may struggle to think of a different context to apply to finding the perimeter.
An alternative context could be: putting a ribbon around a cake and leaving space for decoration.
To help you plan your year 7 maths lesson on: Calculating missing lengths with perimeter of polygons, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 7 maths lesson on: Calculating missing lengths with perimeter of polygons, 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.
Equipment
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.A polygon is a
Q2.True or false? All parallelograms are rhombuses.
Q3.Calculate the perimeter of the square.

Q4.Calculate the perimeter of the rectangle.

Q5.Calculate the perimeter of the kite.

Q6.An irregular polygon has the following side lengths: 5 cm, 8 cm, 6 cm, 7 cm, and 9 cm. What is the perimeter of the polygon?
Assessment exit quiz
6 Questions
Q1.True of false? Summing the length and width of a rectangle gives a result that is half of the perimeter of the rectangle.
Q2.The perimeter of the octagon is 184 cm. What is the length of one side?
