Year 11
Foundation

Find the number of sides when given the sum of interior angles

Year 11
Foundation

Find the number of sides when given the sum of interior angles

Switch to our new maths teaching resources

Slide decks, worksheets, quizzes and lesson planning guidance designed for your classroom.

Play new resources video

Lesson details

Key learning points

  1. In this lesson, we will find the number of sides of a polygon when given only the sum of interior 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.

Loading...

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

4 Questions

Q1.
The sum of interior angles of a polygon is 720º. How many sides does the polygon have?
5
Correct answer: 6
7
8
Q2.
The sum of interior angles of a polygon is 2880º. How many sides does the polygon have?
15
16
17
Correct answer: 18
Q3.
The sum of interior angles of a regular polygon is 3960º. What is the size of each interior angle of the regular polygon?
150º
Correct answer: 165º
170º
175º
Q4.
The sum of interior angles of a regular polygon is 5040º. What is the size of each exterior angle of the regular polygon?
100.8º
Correct answer: 12º
168º
79.2º