If the line segments are straight, then it is a triangle.
A 5 sided pentagon
A triangle.
I believe it may be called a diagonal.
A Polygon! Tah-dah! -Andrew D.
A closed figure made up of line segments is called a polygon. The segments in a polygon are called sides or edges.
a closed figure with all straight line segments is called a polygon.
a polygon
Polygon.
If the line segments are straight, then it is a triangle.
A 5 sided pentagon
A triangle.
A pentagon has five line segments.
It is called its perimeter.
That is called a polygon.
I believe it may be called a diagonal.
a closed plane figure with 3 or more line segments is a polygon