**
Angle
** -
The union of two rays with a common vertex.

**
Coordinate Plane
** -
Any plane with two perpendicular intersecting
lines. The point of intersection of the lines is called the origin and the
location of any point in the plane can be measured along the two lines, or
axes.

**
Degree
** -
A unit of measure for angles. 360 degrees equals one revolution and
2*Π*
radians.

**
Initial Side
** -
The side of an angle from which the rotation begins; the initial
position of the ray whose rotation creates the angle.

**
Magnitude
** -
The length of a vector

**
Minute
** -
A subdivision of a degree. One minute is equal to

degrees.

**
Ordered Pair
** -
The $x$-coordinate and $y$-coordinate, placed together between parentheses
and separated by a comma. An ordered pair specifies a location in the
coordinate plane.

**
Origin
** -
The intersection of the $x$-axis and $y$-axis in a coordinate plane.
The location of the origin is (0,0).

**
Plot
** -
To draw a point in the coordinate plane at a specific location. Points are
plotted in the coordinate plane.

**
Quadrant
** -
One of the four regions in the coordinate plane created by the intersection
of the axes

**
Quadrantal Angle
** -
An angle in standard position whose terminal side lies along one of
the axes

**
Radian
** -
A unit of measure for angles.
2*Π*
radians equals one revolution and
360 degrees.

**
Ray
** -
A part of a line with a fixed endpoint on one end that extends without bound in
the other direction.

**
Revolution
** -
A rotation of the magnitude such that the initial side of an angle
coincides with the terminal side; one complete rotation. One revolution
equals 360 degrees and
2*Π*
radians.

**
Second
** -
A subdivision of a degree. One second is equal to

degrees,
or

minutes.

**
Side
** -
One of the rays that makes up an angle (is a side of the angle).

**
Standard Position
** -
The location of an angle such that its vertex lies at the origin and
its initial side lies along the positive $x$-axis.

**
Terminal Side
** -
The side of an angle after rotation; the final position of the ray
whose rotation created an angle.

**
Vector
** -
A line segment with a starting point and an endpoint that represents motion in
the direction of the endpoint, and which lies in a specific position such that
its direction is fixed.

**
Vertex
** -
The common endpoint of two rays that form an angle

**
x-axis
** -
One of the two perpendicular lines that form the coordinate plane; usually
the x-axis lies in a horizontal position.

**
x-component
** -
The magnitude of a vector in the
*x*
direction.

**
x-coordinate
** -
The distance between a point and the y-axis.

**
y-axis
** -
One of the two perpendicular lines that form the coordinate plane; usually
the y-axis lies in a vertical position.

**
y-component
** -
The magnitude of a vector in the
*y*
direction.

**
y-coordinate
** -
The distance between a point and the x-axis.