there is no such thing
sometimes parallel.
Arachnids have two body segments, the abdomen and......
That the two segments are equal.
A set of points, lines, line segments, rays or any other geometrical shapes that lie on the same plane.
They have two body segments and four leg segments.
congruent segments
Arachnids have two body segments, the abdomen and......
two single segments
The midpoint.
If two line segments are congruent then they have the same length.
Polygon
They can be, and are, "skew". If they are not lines, they cannot be "skew lines".