A diagonal
diagonal
Perpendicular
diagonal
It's a straight line for example within a square that joins opposite corners
A line is a straight path that extends infinitely or endlessly in opposite directions. A straight path that joins two points is called a line segment.
diameter
A bimedian is a line which joins the midpoints of opposite sides of a quadrilateral or tetrahedron.
Diameter Diameter radius
A straight line that joins one vertex to another vertex.
bisector?
mid-segment
The Indian Ocean joins to the Southern Ocean at the southwestern corner of Western Australia.