They are the common tangents to the circles.
it intersects the segment joining the centers of two circles
no
skew
perpendicular bisector
A bisector.
it intersects the segment joining the centers of two circles
intersecting lines
no
skew
an intersecting line segment is when two line segments cross together
perpendicular bisector
A bisector.
It's when two lines cross eachother
A triangle is not a segment joining a vertex and the midpoint of the side opposite the vertex.
A line segment joining two adjacent vertices of a polygon is called an edge or a side. A line segment joining two non-adjacent vertices is called a diagonal.
it depends on how long or how many joining segments it has. normally one line segment contains only one midpoint. Unless it has a joining segment there is only one midpoint.
chord