Year 11
Core

Find missing angles when two or more polygons are joined

Year 11
Core

Find missing angles when two or more polygons are joined

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Lesson details

Key learning points

  1. In this lesson, we will apply regular polygon knowledge to find missing angles when two or more polygons are joined together.

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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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

4 Questions

Q1.
The diagram shows two hexagons joined. Calculate the size of the angle marked b.
An image in a quiz
Correct answer: 120º
144º
60º
90º
Q2.
A regular pentagon and a regular hexagon are joined. Calculate the size of angle a.
An image in a quiz
105º
117º
Correct answer: 132º
144º
Q3.
An octagon and a nonagon are joined. Calculate the size of the angle labelled g.
An image in a quiz
105º
117º
75º
Correct answer: 85º
Q4.
Calculate the size of the angle marked.
An image in a quiz
Correct answer: 12º
15º
18º
27º