Year 11
Core

Finding the sum of interior angles in a polygon

Year 11
Core

Finding the sum of interior angles in a polygon

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Lesson details

Key learning points

  1. In this lesson, we will calculate the sum of interior angles in polygons, and apply this to find missing angles.

Licence

This content is made available by Oak National Academy Limited and its partners and licensed under Oak’s terms & conditions (Collection 1), except where otherwise stated.

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5 Questions

Q1.
What is the sum of exterior angles of any polygon?
180º
Correct answer: 360º
540º
Different with each polygon
Q2.
Calculate the size of angle a.
An image in a quiz
15º
Correct answer: 30º
67º
73º
Q3.
Calculate the size of angle b.
An image in a quiz
134º
Correct answer: 44º
48º
98º
Q4.
4. What is the size of each exterior angle of a regular 15 sided polygon?
Correct answer: 24º
42º
48º
72º
Q5.
5. A regular polygon has an exterior angle of 30º. How many sides does it have?
10
Correct answer: 12
14
16

4 Questions

Q1.
What is the sum of interior angles of a 20-sided shape?
1800º
2880º
Correct answer: 3240º
3600º
Q2.
What is the sum of interior angles of a 9-sided shape?
Correct answer: 1260º
1620º
1980º
900º
Q3.
What is the missing angle, labelled x?
An image in a quiz
114º
33º
Correct answer: 66º
Q4.
What is the size of each interior angle in a regular octagon?
Correct answer: 135º
225º
45º
90º