Each interior angle of the regular 5 sided polygon measures 108 degrees
Hint: in a regular polygon interior plus exterior = 180o, always.
It is a regular 20 sided polygon
If exterior angles are 120 then interior angles must be 60 so you have an equilateral triangle
There is no regular polygon with an interior angle of 20o. If the interior angle is 120o then there are six sides and the sum of the angles is 720o.
If it's a regular polygon then each interior angle measures 120 degrees.
360
cheat!
Each interior angle measures 108 degrees and the 5 angles of the regular pentagon add up to 540 degrees
A four-sided regular polygon (square or rectangle) has 900 interior angles.
The polygon will have 12 equal sides and each interior angle measures 150 degrees.
Because it's a 6 sided polygon and as a regular polygon each of its interior angles measures 120 degrees