A twelve pointed star is made by extending the sides of a regular 12-sided polygon (a dodecagon). What is the measure of the grey angle?
30 degrees because exterior angle of any regular polygon =360 divided by number of sides. So 360/12=30
A five pointed star is made by extending sides of a regular pentagon. What fraction of star on right is shaded yellow?
The ratio between the exterior angle and the interior angle of a regular polygon is 2 : 3 . Find the number of sides of the polygon.
In the regular decagon (10-sided polygon) below, find the percentage of the shaded area.