Geometry symbols - Maths

The symbols that denote the properties and configurations of geometric shapes are known as geometry symbols.

Mathematics deals with two basic types of geometry-

Plane geometry: - For geometric shapes like triangles, circles, and lines.
Solid geometry: -For three-dimensional geometric shapes like spheres, cubes, and cuboids.

List of geometric shapes and their symbols

Symbol	Symbol name	Meaning	Example
∠	angle	formed by two rays	∠ABC = 30º
∟	right angle	= 90º	α = 90º
<\|	spherical angle		AOB = 30º
´	arc minute	1º = 60´	α = 60º59′
º	degree	1 turn = 360º	α = 60º
´´	arc second	1´ = 60´´	α = 60º59’59”
→ AB<	ray	line that start from point A
AB	line segment	the line from point A to point B
\|	perpendicular	perpendicular lines (90º angle)	AC \| BC
≅	congruent to	equivalence of geometric shapes and size	∆ABC ≅∆XYZ
\|\|	parallel	parallel lines	AB \|\| CD
Δ	triangle	triangle shape	ΔABC ≅ΔBCD
~	similarity	same shapes, not the same size	∆ABC ~∆XYZ
π	pi constant	π = 3.1415	2654… is the ratio between the circumference and diameter of a circle c = π·d = 2·π·r
\|x–y\|	distance	distance between points x and y	\| x–y \| = 5
grad	grads	grads angle unit	360º = 400 grad
rad	radians	radians angle unit	360º = 2π rad
∦	Not parallel to	Non-parallel lines	AB CD ( read as AB and CD are non-parallel lines)
□	Quadrilateral	The shape of any quadrilateral	/_/ ABCD
g	gradians / gons	grads angle unit	360º = 400g
∴	Therefore	a=b∴b=a	a equals b, therefore b equals a

A student has to make sure to memorize these symbols to diversify their knowledge. These symbols come in handy in every field where mathematics is dominant.

Advantages of geometric symbols

Various geometric symbols are used in engineering for defining and communicating various shapes and figures, such as

Type of control	Geometric characteristics
Form	Straightness
Form	Flatness
Form	Circularity
Form	Cylindricity
Location	Symmetry[f][g]
Location	Position
Location	Concentricity[f]
Orientation	Perpendicularity
Profile	Profile of a line
Orientation	Angularity
Orientation	Parallelism
Profile	Profile of a surface
Run-out	Circular run-out
Run-out	Total run-out

Production industrialists use it to mark the degree of precision and accuracy during manufacturing machines and products.
It is used by Indian Standard Organisation (ISO) to mark basic standards of products so that everyone can understand them. ISO marks are universal.
They reduce the space needed for writing long descriptions. Usage of geometric symbols takes less space and is clearer to understand and read.

Disadvantages of geometric symbols

People who are not aware of these symbols may find them challenging to understand.
Misreading these symbols can alter manufacturing and production processes, delaying the work or producing the wrong items.
Two or more symbols represent some geometric definitions. This can confuse the reader to understand what the symbol wants to convey.
Forced usage of symbols can create problems while understanding descriptions of the products.
Most customers prefer detailed descriptions rather than using geometric symbols that can create a mess for industrialists.