Answer:

Explanation:
An angle is formed by three vertices.
Starting with
as fixed vertices and changing the
vertex gives us angle of the first line mentioned there.
Starting with
as fixed vertices and changing the
vertex gives us angle of the second line mentioned there.
Starting with
as fixed vertices and changing the
vertex gives us angle of the third line mentioned there.
Starting with
as fixed vertices and changing the
vertex gives us angle of the fourth line mentioned there.
Starting with
as fixed vertices and changing the
vertex gives us angle of the fifth line mentioned there.
Starting with
as fixed vertices and changing the
vertex gives us angle of the last line mentioned there.
Thus those are the maximum possible angles.