Meaning & use
coplanar
Last updated
Meaning
adjectivenot comparablemathematics
Lying in the same flat surface, as points, lines, or shapes that can all be drawn on a single sheet of paper.
Grammar: Not comparable: shapes are either coplanar or not; often used after be.
Patterns
- coplanar with something
Any three points that are not in a line are coplanar.
The two lines are coplanar, so they either cross or run parallel.
The architect checked that the four corners were coplanar.
Common combinations
- coplanar points
- Four coplanar points can lie on one flat sheet.
- coplanar lines
- Coplanar lines either intersect or never meet.
- coplanar vectors
- Coplanar vectors can be drawn in one plane.
- coplanar forces
- The beam is acted on by coplanar forces.
Synonyms and how they differ
- planar
- Planar describes something that lies in or belongs to a plane, while coplanar says several things share the same plane.
- flat
- Flat is an everyday word for a level surface, while coplanar compares positions of several objects.
Opposites
Word family
Commonly confused: coplanar or collinear? coplanar or coplaner?
coplanar vs collinear
Collinear points lie on one straight line, while coplanar points lie on one flat surface.
coplanar vs coplaner
This is a misspelling; the correct form ends in -ar.
Practice
Two lines that are neither parallel nor intersecting in three-dimensional space are not ____.
Choose one answer.
Skew lines cannot lie in a common plane, so they are not coplanar. Collinear is tempting but means on the same line, which is a different condition.
Make it your own
Write a sentence using “coplanar”, then check it and compare it with the examples above.