Myths about teaching can hold you back
- Year 10•
- Higher
Checking and securing understanding of the parts of a circle
I can identify the parts of a circle, including finding the area and perimeter of a sector.
- Year 10•
- Higher
Checking and securing understanding of the parts of a circle
I can identify the parts of a circle, including finding the area and perimeter of a sector.
Lesson details
Key learning points
- A chord splits the circle into two uneven pieces
- The smaller piece is the minor segment and the larger is the major segment
- Using fractions, you can calculate the area of a sector of a circle and you can calculate the curved length of a sector
- To find the perimeter, you will need to add the radius twice
- An exact answer may be given in terms of π
Keywords
Subtended - An angle can be subtended by a line segment or curve. The legs of the subtended angle meet the endpoints of the line segment or curve.
Common misconception
Pupils may think that every line segment that touches a circle exactly once is a tangent (even when it is not perpendicular to the radius at that point).
If unsure, try extending the line segment to beyond the edges of the circle to check whether it would intersect the circle again.
To help you plan your year 10 maths lesson on: Checking and securing understanding of the parts of a circle, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 10 maths lesson on: Checking and securing understanding of the parts 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 4 maths lessons from the Circle theorems unit, dive into the full secondary maths curriculum, or learn more about lesson planning.
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.What is the dashed line segment on this circle called?

Q2.The length of the diameter of this circle is cm.

Q3.The diameter of a circular fence is greater than 8 metres long. Which of these are possible lengths of the radius of this fence?
Q4.A semicircular sector has been cut from a full circle of equal radius.
What fraction of the full circle is this sector?
Q5.This sector has been cut from a circle.
What fraction of the full circle is this sector?

Q6.This circular sector is broken down into two straight line segments and an arc.
The perimeter of this arc is cm.

Assessment exit quiz
6 Questions
Q1.What is the dashed line segment on this circle called?

Q2.What is the shaded region on this circle called?

Q3.Which of these statements are always correct?
Q4.The size of the angle subtended by chord AB is degrees.

Q5.The size of the angle subtended by chord AC is degrees.
