Geometry 1.1 - 1.4

Point

A location

Line

A set of points that extend in both directions forever

Line Segment

Part of a line with 2 end points

Ray

Part of a line with 2 points

Plane

A flat surface that extends to infinity

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End point

A point that marks the end of a segment or line

Between

A point on a line segment between the endpoints

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Midpoint

A point thats the exact center of a line segment

Opposite rays

2 rays that point in opposite directions that share an endpoint

Midpoint Formula

( x1+ x2 /2 , y1+ y2 /2 )

Non collinear

Points that are not on the same line

Coplanar

Points on the same plane

Collinear

Points on the same line

Noncoplanar

Points not on the same plane

Angle

the space between 2 intersecting lines

vertex

a point where 2 or more line segments meet

straight angle

180 degrees

angle addition postulate

the sum of 2 angles that add up to a larger angle (CAB+BAD=CAD)

Segment Addition postulate

2+ line segments will add up to the length of a longer segment (AB+BC=AC)

Acute

an angle less than 90 degrees

obtuse

an angle greater than 90 degrees

Right angle

an angle equal to 90 degrees

Angle Bisector

A line that cuts down the middle of an angle

Distance formula

**√(x2 − x1 ) /2 + (y2 − y1 ) /2**

Inductive Reasoning

making a prediction based on a pattern

Conjecture

A statement that is believed to be true but lacks proof.

Counterexample

an example that proves the conjecture to be false

Perpendicular Bisector

\

a line that intersects another line and forms two segments of equal length.

Congruent

equal