Introduction To Geometry Summary Sheet printable pdf download

Introduction To Geometry Summary Sheet

Ch 1 Summary

Name ____________________________

Chapter 1: Introduction to Geometry Summary Sheet

Undefined Terms

General Terms

point An undefined term thought of as a location with no

intersect To cut or cross.

size or dimension. It is the most basic building block of

bisect To divide into two congruent parts.

geometry. In a two-dimensional coordinate system, a

counterexample An example that shows a conjecture to be incorrect or a

point’s location is represented by an ordered pair of

definition to be inadequate.

numbers (x, y).

adjacent means next to.

line An undefined term thought of as a straight, continuous

adjacent angles Two angles that share a common vertex, share a common

arrangement of infinitely many points extending forever

side and have no common interior points.

in two directions. A line has length, but no width or

consecutive (angles, sides, or vertices of a polygon) Two angles that share

thickness, so it is one-dimensional.

a common side, two sides that share a common vertex, or two vertices

plane An undefined term thought of as a flat surface that

that are the endpoints of one side.

extends infinitely along its edges. A plane has length and

width but no thickness, so it is two-dimensional.

Related Terms

collinear On the same line.

Symmetry

coplanar In the same plane.

symmetry The property that a figure coincides with itself under a

transformation that preserves size and shape.

reflectional symmetry The property that a figure coincides with itself under

a reflection. Also called line symmetry or mirror symmetry.

line of symmetry The line of reflection of a figure having reflectional

symmetry.

bilateral symmetry Reflectional symmetry with only one line of symmetry.

rotational symmetry The property that a figure coincides with itself under

some rotation. If the angle of rotation is 360/n degrees for some positive

integer n, the symmetry is called n-fold rotational symmetry.

Introduction To Geometry Summary Sheet