# plane

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## Origin of plane

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^{1}; (in def. 5), shortened form of airplane, aeroplane, or hydroplane; (verb) late Middle English planen “(of a bird) to soar” (compare Middle French planer ); akin to plain

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## OTHER WORDS FROM plane

planeness, noun## Words nearby plane

## Other definitions for plane (2 of 3)

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## Origin of plane

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^{1}; Middle English verb plane(n), plaine, pleine, from Middle French planer or directly from Late Latin plānāre

## Other definitions for plane (3 of 3)

## Origin of plane

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## MORE ABOUT PLANE

## What does *plane* mean?

In geometry, a *plane* is a flat, two-dimensional surface with an infinite height and width. It’s one of the basic concepts of geometry.

Think of a flat sheet of paper. A physical sheet of paper has three dimensions: length, width, and (a small) height. If that sheet of paper had zero height and its length and width extended forever, it would be a *plane*. Obviously, such a shape is theoretical—it’s used as a basis for geometric calculations.

A *plane* is one of several basic concepts students need to begin to understand geometry. Another is a *point*. Unlike a *plane*, it has no dimensions, such as length or width. It is found by using coordinates. A third concept is a *line.* Like a *plane,* a line also extends forever but only in two directions.

Understanding what a *plane* is matters because angles and two-dimensional shapes, such as squares, triangles, and circles, are represented as points, lines, and line segments on a *plane.* It also helps you understand three-dimensional space and three-dimensional objects, which have height as well as length and width. *Plane* has several other meanings, some of which have different roots. More generally, it can refer to any flat or level surface.

## Why is *plane* important?

The first records of the word *plane* in a mathematical sense come from the early 1600s. It comes from the Latin *plānum,* meaning “flat surface,” which is a noun formed from the Latin adjective *plānus,* meaning “flat.”

*Planes* and many other basics of geometry are often credited to the Greek mathematician Euclid, who lived around the year 300 B.C. Euclid developed the idea of a *plane*, along with other fundamental concepts of geometry, such as points, lines, and two-dimensional shapes. All two-dimensional geometry exists on a *plane*. Because of this, geometry that deals with two-dimensional shapes is called *plane* geometry.

The other major type of geometry is solid geometry, which involves three-dimensional space and shapes, such as cubes and cylinders.

## Did you know ... ?

Euclid’s conception of geometry, known as Euclidean geometry, provided almost the entire foundation of geometry for over 2,000 years until mathematicians explored non-Euclidean geometry in the 1800s.

## What are real-life examples of *plane*?

We encounter *planes* all the time in everyday life, even though we might not use geometric terms to describe them.

Should I continue studying statistics or should I study plane geometry? pic.twitter.com/SxfFKgRL2i

— aq lang to si joysan (@luciengf__) May 23, 2020

Very cool moment in Plane Geometry today when some of my students starting investigating the Golden Ratio with their own proportions! They started measuring the proportion of their hand to their forearm to discover the Golden Ratio in human anatomy for themselves. #207Learn pic.twitter.com/goEYAMOSrc

— Sarah Kendeigh (@KendeighSarah) January 30, 2020

Learning Three.js by recreating Matt Shlian's sculptures. https://t.co/XKRXY1R0FE

Process so far:

Start with a plane geometry.

Subdivide it to create sculpture like geometry.

Compute normals.

Use normals to colour the faces. pic.twitter.com/JuJxKJZtaP— Varun Vachhar (@winkerVSbecks) June 7, 2020

## What other words are related to *plane*?

## Quiz yourself!

**In geometry, a plane is a two-dimensional surface with:**

A. infinite width and height.

B. infinite width and length.

C. infinite length and height.

D. infinite width, length, and height.

## How to use plane in a sentence

## British Dictionary definitions for plane (1 of 3)

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## Derived forms of plane

planeness, noun## Word Origin for plane

## British Dictionary definitions for plane (2 of 3)

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## Word Origin for plane

## British Dictionary definitions for plane (3 of 3)

## Scientific definitions for plane

## Cultural definitions for plane

A geometrical location having only two dimensions — length and width (no height). (See coordinates and plane geometry.)