The sum of the exterior angles is 360 so if each is 120 we know 360/120=3.
This tells us there are 3 exterior angles.
The sum of the interior angles in a triangle is 180 degrees.
It will have 3 interior angles of 60 degrees that add up to 180 degrees and it is an equilateral triangle.
Yes a square is a regular 4 sided polygon
360 degrees
The interior angles of a 36 sided polygon add up tp 6120 degrees
"poly" just means "many". How many sides? Interior angles of any n-sided polygon total 180n - 360 degrees, usually expressed as "2n -4 right angles"
octagon
A decagon
A triangle has three angles.
There are 22
A polygon with 6 sides is an hexagon
any ellipse, any pie-wedge of a circle, etc.
A four sided polygon can be a square, a parallelogram, a rectangle, a rhombus or a kite.