CCGPS Coordinate Algebra Unit 5 Vocab

Angle

A figure created by two distinct rays that share a common endpoint (also known as a vertex).

Angle of Rotation

The amount of rotation (in degrees) of a figure about a fixed point such as the origin.

Bisector

A point, line or line segment that divides a segment or angle into two equal parts.

Circle

The set of all points equidistant from a point in a plane.

Congruent

Having the same size, shape and measure.

Corresponding angles

Angles that have the same relative position in geometric figures.

Corresponding sides

Sides that have the same relative position in geometric figures.

Endpoint

The point at each end of a line segment or at the beginning of a ray.

Image

The result of a transformation.

Intersection

The point at which two or more lines intersect or cross.

Isometry

a distance preserving map of a geometric figure to another location using a reflection, rotation or translation.

Line

One of the undefined terms of geometry that represents an infinite set of points with no thickness and its length continues in two opposite directions indefinitely.

Line segment

A part of a line between two points on the line.

Parallel lines

Two lines are parallel if they lie in the same plane and do not intersect.

Perpendicular lines

Two lines are perpendicular if they intersect to form right angles.

Point

One of the basic undefined terms of geometry that represents a location. A dot is used to symbolize it and it is thought of as having no length, width or thickness.

Pre-image

A figure before a transformation has taken place.

Ray

A part of a line that begins at a point and continues forever in one direction.

Reflection

A transformation of a figure that creates a mirror image, "flips," over a line.

Reflection Line (or line of reflection)

A line that acts as a mirror so that corresponding points are the same distance from the mirror.

Rotation

A transformation that turns a figure about a fixed point through a given angle and a given direction, such as 90� clockwise.

Transformation

The mapping, or movement, of all points of a figure in a plane according to a common operation, such as translation, reflection or rotation.

Translation

A transformation that slides each point of a figure the same distance in the same direction.

Vertex

The location at which two lines, line segments or rays intersect.