Geometry Definitions, Chapter 1

Front 1

Inductive reasoning

Back 1

method used for drawing conclusions from a limited set of observations

Front 2

Deductive reasoning

Back 2

uses logic to draw conclusions from statements already accepted as true

Front 3

collinear

Back 3

points are collinear if there is a line that contains all of them

Front 4

noncollinear

Back 4

points are noncollinear if no single line contains them all

Front 5

coplanar

Back 5

points are coplanar if there is a plane that contains them all

Front 6

concurrent

Back 6

lines are concurrent if they contain they same point

Front 7

angle

Back 7

pair of rays with the same endpoint

Front 8

ray

Back 8

part of a line that extends endlessly in one direction

Front 9

line segment

Back 9

part of a line bounded by two endpoints; one-dimensional

Front 10

polygon

Back 10

two-dimensional; lies in a plane; bounded by line segments

Front 11

polyhedron

Back 11

three-dimensional; exists in space; bounded by polygons

Front 12

perimeter

Back 12

perimeter of a polygon is the sum of the lengths of its sides

Front 13

area

Back 13

the surface included within a set of lines; specifically, the number of unit squares equal in measure to the surface

Front 14

area of rectangle

Back 14

A=lw

Front 15

circle

Back 15

set of all points in a plane that are a fixed distance from a given point in the plane

Front 16

radius

Back 16

fixed distance from center of circle and any point on it

Front 17

bisect

Back 17

to divide it into two equal parts

Front 18

protractor

Back 18

measures angles in degrees

Front 19

constructions

Back 19

geometric drawings made with compass and straightedge