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26 terms

This is the vocabulary for Geometry by Ray Jurgensen, Richard Brown, and John Jurgensen published by McDougal Littell.

Equidistant

equally distant from two points

Undefined terms

Point, line, plane

Collinear

lying on the same line

Coplanar

lying in the same plane

Intersection (of two figures)

The set of points that are in both figures

Through any two points there is

Exactly one line

Through any three non collinear points there is

Exactly one plane

Through any three points there is

At least one plane

Ray

A straight line extending from a point

Oblique plane

A diagonal or tilted plane

Intersect

When at least two lines, rays, or segments meet at one point.

Non coplanar

Not in the same plane

Segment addition postulate

If B is between A and C, then AB+BC=AC

Angle addition postulate

if point B lies in the interior of <AOC then m<AOB + m<BOC = m<AOC. If ∠AOC is a straight angle and B is not on ray AC, then m∠AOB + m∠BOC = 180.

Sides of an angle

the two rays that form the angle

Vertex

The common endpoint of an angle

Acute angle

an angle less than 90 degrees but more than 0 degrees

Right angle

an angle that measures 90 degrees

Obtuse angle

an angle between 90 and 180 degrees

Straight angle

an angle that measures 180 degrees

Protractor postulate

On line AB in a given plane, choose any point O between A and B. Consider →OA and →OB and all the rays that can be drawn from O on one side of line AB. These rays can be paired with the real numbers from 0 to 180 in such a way that: a) →OA is paired with 0, and →OB with 180. b) If →OP is paired with x, and →OQ with y, then m∠POQ = |x - y|.

Congruent angles

angles that have the same measure

Adjacent angles

are a pair of angles with a common vertex and a common side, but no common interior points

Bisector of an angle

the ray that divides the angle into two congruent adjacent angles

If two lines intersect then

Exactly one plane contains the lines

Theorem

An important proved statement