Myths about teaching can hold you back
- Year 10•
- Higher
Forming equations with angles
I can form and solve equations using my knowledge of angles and polygons.
- Year 10•
- Higher
Forming equations with angles
I can form and solve equations using my knowledge of angles and polygons.
Lesson details
Key learning points
- Missing angles can be found in polygons using knowledge of exterior and interior angles.
- A missing angle can be represented with an unknown.
- Algebraic statements can be written about the missing angles in polygons.
Keywords
Interior angle - An interior angle is an angle formed inside a polygon by two of its edges.
Exterior angle - An exterior angle is an angle on the outside of a polygon between an extension of an edge and the adjacent edge.
Common misconception
Alternate angles are always equal to each other.
Alternate angles are equal when a transversal intersects parallel lines. If the transversal intersects a pair of lines that are not parallel then the alternate angles will not be equal.
To help you plan your year 10 maths lesson on: Forming equations with angles, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 10 maths lesson on: Forming equations with angles, 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 Angles unit, dive into the full secondary maths curriculum, or learn more about lesson planning.
Licence
Prior knowledge starter quiz
6 Questions
Q1.The exterior angles of any polygon __________ sum to 360°.
Q2.The interior angles of any polygon __________ sum to 360°.
Q3.An interior angle and its adjacent exterior angle __________ sum to 360°.
Q4.A regular polygon has exterior angles of size 24°. The polygon has sides.
Q5.The size of each exterior angle of a regular octagon is °.
Q6.The regular polygon that has interior angles that are equal to its exterior angles is a .
Assessment exit quiz
6 Questions
Q1.Match each description to the correct statement.

unsimplified expression for angle sum -
5$$x$$ + 46 + 74
simplified expression for angle sum -
5$$x$$ + 120
equation for angle sum -
5$$x$$ + 120 = 180
solution for $$\text{ }x$$ -
$$x$$ = 12
angles in triangle -
46°, 60°, 74°
Q2.Find the value of $$x$$.

Q3.Find the value of $$x$$.

Q4.Find the value of $$x$$. Give your answer correct to 3 significant figures.

Q5.The value of $$x$$ is .

Q6.Find an equation for $$y$$ in terms of $$x$$.
