Regular polygons
Answers are for parents and teachers.
1
What is the interior angle of a regular nonagon (degrees)?
140
2
A regular polygon has interior angle 162°. How many sides does it have?
20
3
What is the central angle of a regular octagon (degrees)?
45
4
The interior angles of a regular polygon add up to 1080°. How many sides does it have?
8
5
Why do the interior and exterior angles of a regular polygon at a vertex add up to 180°?
The exterior angle is adjacent to the interior angle, and adjacent angles add up to 180°.