What are the Various Geometry Symbols in Math? (Examples) - BYJUS

Geometry Symbols

Geometry is the study of the shape of an object. The objects you see in everyday life, such as books, windows, buildings, bridges, stars, and so on can be described with the help of geometry. Geometry is composed of symbols, shapes, numbers, and variables. Here we will focus on the symbols used in geometry....Read MoreRead Less

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What is “Geometry”?

Geometry is the branch of mathematics that describes the configuration of objects in terms of their shape, size, angle, and dimension. Geometry also defines the position of an object and its distance from a reference point.

 

Geometry is applied in various fields, including construction, interior designing, graphic designing, the orbit of the earth, planetary motion, and so on.

 

The calculations related to the motion of the sun, timings of the sunrise and the sunset are also based on geometry.

 

Geometry is broadly classified into two types: 

  1. Plane geometry  
  2. Solid geometry

 

Plane geometry deals with two-dimensional figures like squares, circles, rectangles, triangles, and so on. Solid geometry, on the other hand, deals with the study of three-dimensional shapes like cubes, cuboids, cylinders, cones, spheres, and so on.

 

all_shapes

 

 

all_3d_figures

Geometry Symbols

Various signs are used to represent geometric figures or quantities. These signs are known as geometry symbols. Let us explore these symbols in detail:

 

S.NO

Geometry symbol

Symbol name 

Meaning or Definition of the symbol

   Example: 

1

.

      Point

A dot represents a point. It is used to locate the position of an object.

Point A, point B

2

\(\leftrightarrow\)  Infinite Line

A line connecting an infinite number of points and  extending infinitely in both directions.

3

Line segment

A line starting from one point, say ‘A’ and terminating at another point, say ‘B’.

 

4

\(\rightarrow \)

Ray

Starts at one point and extends infinitely with no endpoint. 

ray1

AB_ray

5

Angle

Formed by the intersection of two rays.

\(\angle 1 = 20^{\circ},\)

\(\angle {ABC}\)\(=110^{\circ},\) \(\angle A=40^{\circ}\)

6

Right angle

Special angle which measures \( 90^{\circ}\).

∟1 \( =90^{\circ}\).

7

0

Degree

Unit of angle measure.

\(\angle 1 = 20^{\circ},\)

\(\angle {ABC}\)\(=110^{\circ},\) \(\angle A=40^{\circ}\)

8

\(\perp \)

Perpendicular

When two lines intersect at  \(90^{\circ}\).

9

\(\left | \right |\)

      Parallel

When two lines never intersect or the distance between them always remains the same.

AB CD

10

Congruent to

Equivalence of geometric shape and size.

∆ABC ≅∆XYZ

11

~

Similar to

Similarity in shape but not in size.

∆ABC ~ ∆XYZ

12

\(\neq \)

Not equal to

When two quantities are not equal.

If \(\angle A=40^{\circ},\) 

\(\angle B=0^{\circ},\)

\(\angle A\neq \angle B\)

13

I A-B I

Absolute value

The distance between point A and point B.

14

π

Pie, a constant term

The ratio of the circumference to the diameter of a circle.

π \(\approx \frac{22}{7}\approx 3.14\) 

15

Δ

Triangle

A polygon with three sides,  three vertices, and three angles.

ΔABC

16

Center of the circle

 

Point A is the center of a circle 

 

17

Arc AB

The arc from point A to point B 

 

Solved Examples

Example 1:
In the figure given below, two parallel lines are intersected by a transversal. Find the ∠B and ∠D.

geo_eg1

Solution: 

Since 40° and ∠D are alternate interior angles, they are congruent.

So, ∠D = 40°

Since 140° and ∠B are alternate interior angles, they are congruent.

So, ∠B = 140°

Hence, ∠D = 40° and ∠B = 140°.

 

Example 2: Compare | -2.5 | and \(\frac{3}{2}\).

Solution:
| -2.5 | = 2.5 [Absolute value]

\(\frac{3}{2}\) = 1.5         [Fraction to decimal]

2.5 > 1.5

So,

| -2.5 | > \(\frac{3}{2}\)

 

Example 3: Evaluate. | -8 + 5 – \(\frac{4}{3}\) |.

Solution: 

 -8 + 5 – \(\frac{4}{3}\) 

 = – 3 – \(\frac{4}{3}\)                             [Simplify]

 =  \(\frac{  –  9  –  4}{3}\)                             [Simplify further]

 = –  \(\frac{13}{3}\)

  So, | -8 + 5 – \(\frac{4}{3}\) | = | – \(\frac{13}{3}\)|    [Absolute value]

Hence, | -8 + 5 – \(\frac{4}{3}\) | = \(\frac{13}{3}\).

 

Example 4: In the triangle given below, find the measure of ∠C.

geometry_eg4

Solution:

In the given triangle, AB \(\perp\) BC, so ∠B = 90°.

∠A + ∠B + ∠C = 180°    [Sum of angles of a triangle]

30° + 90° + C = 180°     [Substitute values]

120° + C = 180°             [Add]

C = 180° – 120°             [Subtract 120 from both sides]

C = 60°   

Hence, the measure of C is 60°.

Frequently Asked Questions on Geometry Symbols

Symbols make it easier to refer to mathematical quantities and express the relationship between them. Symbols not only enhance understanding but also provide a universally perceivable way to represent certain math functions or illustrate a sequence.

A line is a collection of points and is extended in both directions infinitely. It has neither a start point nor an endpoint. The line AB passing through point A and point B extends to infinity in the right as well as in the left direction. The symbol of a line is

                                         geo_faq1                    geo_faq2

The line segment has two endpoints, and it does not extend infinitely in either direction. It is represented as

                                          geo_faq3                   geo_faq4

It may also be represented as  Line Segment

A ray is a line that has one endpoint and the other side of the line extends indefinitely. It is represented by one endpoint and the end by an arrowhead.

The ray originating from A and passing through B is represented as  ray_faq

 

ray2_faqs

 

The ray originating from B and passing through A is represented as  ray3_faqs

 

ray5_faqs

 

[Note: Ray  ray_faq is not same as ray ray3_faqs ]