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Collinear

If three or more points all belong to the same line they are said to be collinear

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Concurrent

If three or more lines contain the same point, they are said to be concurrent

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Between

If B is between A and C,

Then points A, B, C are distinct collinear points and AB + BC = AC

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Same Side

Points B and C are said to be on the same side of point A if A, B, C are collinear and point A is not between point B and C.

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Line Segment

A line segment is a set of two points and all the points between them.

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Ray

A Ray is a set of points consisting of a fixed point of a line and all the points of the line on the same side of the fixed point.

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Opposite Rays

Opposite Rays are two rays of the same line that have a common endpoint and no other point in common.

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Angle

An angle is a set of points consisting of the union of 2 rays with a common endpoint (vertex)

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Interior

A point P lies in the interior of an angle if there exist two points, one on each ray, neither at the vertex, such that the point P is between said two points.

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Congruent Line Segments

Congruent Line Segments are line segments that are equal in measure

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Congruent Angles

Congruent Angles are angles that are equal in measure

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Midpoint

The midpoint of a line segment is a point of the line segment such that 2 segments formed are congruent.

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Line Segment Bisector

A line segment bisector is a line that intersects the line segment at its midpoint.

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Right Angle

A right angle is an angle measuring 90 degrees.

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Acute Angle

An acute angle is an angle measuring less than 90 degrees but greater than 0 degrees

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Obtuse Angle

An obtuse angle is an angle measuring greater than 90 degrees but less than 180 degrees

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Complementary Angles

Complementary Angles are 2 angles the sum of whose measures is 90 degrees.

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Supplementary Angles

Supplementary Angles are 2 angles the sum of whose measuring 180 degrees

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intersect

Two lines are said to intersect of they have a point in common

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Perpendicular Lines

Perpendicular Lines are 2 lines that intersect and forms a right angle

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Angle Bisector

An angle bisector is a ray whose endpoint is the vertex of the angle and that forms 2 congruent angles

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Reversed Midpoint

A point of the line segment that forms 2 congruent segments is the midpoint of the line segment

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Reversed line segment bisector

A line that intersects the midpoint of a line segment is a line segment bisector

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Reversed right angle

A angle whose measure is 90 degrees is a right angle

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Reversed angle bisector

A ray whose endpoint is the vertex of the angle and that forms two congruent angles is an angle bisector.

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Reversed congruent angle

Angles that are equal in measure are congruent

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Reversed congruent line segments

Line segments that are equal in measure are congruent

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Adjacent Angles

Adjacent angles are two angles in the same plane that share a common vertex and a common ray but share no other points.

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Linear Pair

Angles that form a linear pair are 2 adjacent angles such that their non-common rays are mutually opposite.

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