Lines & Angles

According to the Curve Wikipedia article, lines are required to be straight and so-called curved lines should actually be referred to simply as curves [1].

A horizontal line goes side-to-side or forwards-and-backwards, while a vertical line goes up-and-down. A diagonal line can either refer to a slanted line or a line that goes between two nonadjacent corners of a shape or object [2].

Lines intersect if they come together.

When lines intersect, they create one or more angles depending on the length of the lines and the number of lines that are intersecting.

Angles are typically measured in degrees (°). An entire circle is 360°. A right angle is 90°, which is equivalent to a quarter of a circle. A right angle can be symbolized with either a small square or a dot (this is demonstrated in the Right angle Wikipedia article) [3].

Two lines are perpendicular if they form a right angle (this is the case for a horizontal line and a vertical line). Two lines are parallel if they are positioned so that they'd never intersect if continued indefinitely (this is the case for two vertical lines).

Dimensions, Faces, & Bases

A 0 dimensional (0D) object is a point, a 1D object is a line, a 2D object is a flat shape, and a 3D object is non-flat shape.

The different 2D shapes that are on the surface of a 3D shape are called faces.

The term base can be used to refer to the bottom face of an object [4]. The bottom face of an object is typically only considered a base if it can, on its own, keep the object in a steady and stable position. This is why it can be said, for example, that a poor argument is "baseless" and "falls flat on its face".


A polytope is a shape with all flat sides [5]. Some examples of different polytopes are discussed below:

Shape & Object Measurements

The diagonal length of a polytope refers to the length of its longest diagonal or diagonals.

The diameter of a circle refers to its longest length across [10].

An equilateral polygon has all of its sides as the same length, an equiangular polygon has all of its angles as the same number of degrees, and a regular polygon is both equilateral and equiangular [11].

Two objects are similar if they have the same shape and congruent if they have the same shape and size [12].

The term form factor can refer to an object's standardized shape and size [13]. Some examples of objects with a form factor are mentioned in the Form factor Wikipedia article.

Length can refer to the longer measurement of a rectangle, the longest measurement, or the longer base measurement. Width can refer to the shorter measurement of a rectangle, the side-to-side measurement, or the shorter base measurement. Depth can refer to front-to-back or vertical measurement [14] [15] [16] [17] [18 pages 11+60].

Landscape vs. Portrait Orientation

An item that is in landscape orientation is wider-than-taller, whereas an item in portrait orientation is taller-than-wider [19].

Display Pixels & Resolution

Modern-day displays show a picture by creating a grid of congruent rectangular cells. The cells in this grid are known as pixels. When the word resolution is applied to these displays, it's referring to the dimensions, rows, or columns of pixels [20].

Dimension Measurements

Dimension measurements measure the sides of a shape or item. As is mentioned in the Writing article, this website will use an x to separate numbers in dimension measurements, with the x serving as a substitute for the word "by" [21]. Some important examples of dimension measurement are discussed below:

As is demonstrated by these and other examples [14] [15] [16], there's not a universal consensus regarding how to measure shapes, objects, and items. Therefore, in order to measure shapes, objects, and items, the following system will be used for dimension measurements:


3D space is typically measured with three axes: x, y, and z [27]. This is shown in the image below [28]:

3D space image

These axes can also apply to the measurements of objects. For example, HDD, SSD, and SSHD manufacturers will sometimes describe the height of these devices as the z-height to indicate that the height of these devices is the shortest dimension [29] [30] [31] [32] [33] [34].

(C) 2015


1. Curve. Wikipedia.

2. Diagonal. Wikipedia.

3. Right angle. Wikipedia.

4. Base (geometry). Wikipedia.

5. Polygon. Wikipedia.

6. Quadrilateral. Wikipedia.

7. Rhombus. Wikipedia.

8. Polyhedron. Wikipedia.

9. Hexahedron. Wikipedia.

10. Diameter. Wikipedia.

11. Regular polygon. Wikipedia.

12. Congruence (geometry). Wikipedia.

13. Form factor. Wikipedia.

14. Measurement: Length, width, height, depth. Education Development Center, Inc. (C) 1994-2014.

15. Thread started by Herb on May 31, 1999 5:22:02 PM. What is Length in a Rectangle?. Ask Dr. Math. (C) 1994-2015 The Math Forum.

16. Thread started by Kelsey on Dec. 2, 2003 9:08:48 PM. Length or Width?. Ask Dr. Math. (C) 1994-2015 The Math Forum.

17. uspacking. Box Size & How To Measure. Oct. 28, 2011. U.S. Packaging & Wrapping LLC.

18. GDSN Package Measurement Rules Standard. Release 2.1, Oct. 2015. (C) 2015 GS1 AISBL.

19. Page orientation. Wikipedia.

20. Display resolution. Wikipedia.

21. Multiplication sign. Wikipedia.

22. Paper size. Wikipedia.

23. Photo print sizes. Wikipedia.

24. Moto X Pure Edition (2015) - Unlocked Smartphone - Motorola. (C) 2015 Motorola Mobility LLC.

25. DROID Turbo 2 - Shatterproof Android Smartphone - Motorola. (C) 2015 Motorola Mobility LLC.

26. What we do. GS1.

27. Three-dimensional space. Wikipedia.

28. Falcorian. File:Coord planes color.svg. Feb. 14, 2006 7:29 AM. Wikipedia.

29. Patrick Schmid and Achim Roos. 9.5 Versus 12.5 mm: Which Notebook HDD Is Right For You?. May 22, 2010 12:00 AM. Tom's Hardware.

30. The World’s First 7mm, 2.5-Inch Form Factor Drive. Mar. 2012. (C) 2012 Seagate Technology LLC.

31. 600 SSD. May 2013. (C) 2013 Seagate Technology LLC.

32. Making the Move Toward Slim. Aug. 2013. (C) 2013 Seagate Technology LLC.

33. Design Flexibility with 7.0mm Z-Series Drives. Oct. 2013. (C) 2013 HGST, Inc.

34. Kent Smith. Z-height: The shifting landscape of SSDs. Apr. 11, 2014 7:00 AM. (C) 2015 TechSpot, Inc.