Geometry Ch 1.1 Notes

Conjecture – is an unproven statement that is based on observation

Inductive Reasoning – is a process used to make conjectures by looking at patterns

Counterexample – is an example that show a conjecture is false

Geometry Notes Ch 1.2

Undefined Terms – we just describe them

Point – has no dimension, represented by a small dot, (position in space)Line – extends in one dimension, represented by a straight line with arrows on each endPlane – extends in two dimensions, represented by a parallelogram

Point

Plane

Ray

Opposite Rays

Line

Line Segment

Definitions

Collinear Points – are points all on the same line

Coplanar Points – are points all of the same plane

Intersect – if two or more figures have one or more points in common

Intersection – is the set of points the figures have in common

Geometry Ch 1.3 NotesPostulates or Axioms – are rules that are

accepted without proofTheorems – are rules that have been proven

Lengths are equal Segments are congruentAB = AD AB = AD“is equal to” “is congruent to”

Postulate 1 – without the bar means length AB with the bar means line segment. The distance between two points is the absolute value of the difference of the coordinates.

Postulate 2 – Segment Addition Postulate

Distance Formula -

Pythagorean Theorem -

Geometry Ch 1.4 Notes

Angle – consists of 2 different rays that have the same initial point

Measures are equal Angles are congruent

Postulate 4 – Angle Addition Postulate

Classifying angles by their measureAcute angle –Right angle –Obtuse angle –Straight angle –

Adjacent Angles – are 2 angles that share a common vertex and side, but do not have any common interior points in common

Geometry Ch 1.5 NotesMidpoint – is the point that divides a segment in halfBisect – means to cut into two equal parts

Midpoint Formula –

Angle Bisector -

Geometry Ch 1.6 NotesVertical Angles – are 2 angles whose sides are opposite rays of

each other.

Linear Pair – 2 adjacent angles whose noncommon sides are opposite rays

Complementary Angles –

Supplementary Angles -

Geometry Ch 1.7 NotesSquare - P =

A =

Rectangle – P = A =

Triangle - P =A =

Circle - C = A =