Geometries can be ill-defined for several reasons, e.g. circles with a radius of zero, segments that start and end at the same location, etc. See details for a list of conditions that are considered degenerate.

## Details

The following conditions are considered to produce degenerate geometries:

A circle having a radius of zero

An iso-rectangle with zero width or zero height

An iso-cuboid with zero width, zero height, or zero depth

A 2D line with the coefficients being zero

A 3D line that is degenerated to a point

A plane with the coefficients being zero

A ray with the source and the second defining point being equal

A segment with the source and target being equal

A sphere with a radius of zero

A tetrahedron with all vertices being co-planar

A triangle with collinear vertices

## See also

Other Predicates:
`collinear()`

,
`constant_in`

,
`geometry_class`

,
`geometry_turns`

,
`has_intersection()`

,
`in_order()`

,
`location_predicates`

,
`parallel()`