geometry ch 1.1 & 1.2 terms

Definition

An exact unambiguous description of the term, concept, object, or symbol that establishes its exact properties and depends on previously defined terms

Point, line, plane

the building blocks of geometry and are called the undefined terms because theres no way to define them

Point

• A location

• Sizeless

• Represented by a dot

• Named using capital letters

• The basic building block of all geometric objects

Line

• Extends infinitely far in 2 opposite directions

• Has no thickness (infinitely thin)

• One dimensional

• Named by a single letter or a letter & an index

• Usually named by placing a double arrow over 2 points on the line

• Think of an infinitely long piece of string

Plane

• Ex: an infinite floor/ wall/ desktop

• Perfectly flat but extends infinitely far in all directions

• Use a 4-sided figure with a capital letter or 3 noncollinear points in it to name a plane

• 2 dimensional

Space

The set of all points and is not flat

Collinear

A collection of points is a ___ set if each point belongs to the same line

Figure

Any collection of points & can also be a visual display of these as well

Set

Any collection of objects

Elements

Objects that make up a set and make them equal if they contain all the same of these objects

Types of way to name a set

• Listing elements in braces {red, blue, yellow}

• Using braces and ellipses if elements follow a pattern {1, 3, 5, …, 99}

• Set-builder notation {x € all real numbers: x² > 9}

Intersection

Contains all common elements of two sets

Disjoint

Two sets that have no common elements

Empty set

Intersection of two sets that are disjoint