# vs.eyeandcontacts.com

## Space and Properties of Space Terms

Axis (axes): A reference line (or pair of lines) from which distances are measured on a coordinate grid.

Clockwise: In the same direction as the rotation of the hands of a clock.

Collinear: A set of points lying in a straight line.

Coordinate grid: A 2-dimensional grid in which location is described by its distances from the X and Y axes.

Coordinates: An ordered pair of numbers that gives the location of a point in a coordinate grid.

Coplanar: In the same plane.

Congruent:
Having exactly the same size and shape.

Counter-clockwise: In a direction opposite to the direction that the hands of a clock rotate.

Horizontal: Parallel to the horizon.

Intersect: To cross over one another.

Mid-point: The middle point of a line segment.

Origin: The intersection of the X-axis and the Y-axis in a coordinate plane. Its coordinates are (0,0).

Parallel lines: Lines that never meet no matter how far they are extended.

Perpendicular: Forming right angles.

Perpendicular bisector: A line that divides a line segment in half and meets the segment at right angles.

Plane: A flat surface. A plane extends indefinitely in all directions.

Point: An exact location in space.

• Any of the four sections of a coordinate grid that are separated by the X and Y axes.
• A quarter of a circle or its circumference.

Vertical: Perpendicular to the horizon.

X - Axis:
The horizontal axis of the graph.

Y - Axis:
The vertical axis of the graph.