Yes.
Hexagon
a polygon is convex
If the polygon (not ploygon!) has n vertices, the sum of the angles is (n-2)*pi radians or (n-2)*180 degrees.
As many corners as sides.
Yes.
A triangle.
No, it's a POLYGON.
Hexagon
PENTAGON!!!
a megcagon
a tetradecagon
heptagon
Pentagon
a polygon is convex
pentagon
as many as it wants