A closed plane figure having six sides
Related Terms 
SPREAD
The divergence of the air stream in a horizontal or vertical plane after it leaves the outlet.

END CAP
A ported or closed cover for the end of a filter element.

GYRE
A closed circulatory system, but larger than a whirlpool or eddy

HORIZONTALLY POLARIZED WAVE
A plane polarized electromagnetic wave in which the electric field vector is in a horizontal plane.

HORIZONTAL
Parallel to the plane of the horizon; perpendicular to the direction of gravity

INCLINATION OF AN ORBIT
1. See INCLINATION, definition 2. 2. As defined by the International Telecommunication Union (ITU), the angle determined by the plane containing an orbit and the plane of th

INCLINATION
1. The angle which a line or surface makes with the verti cal, horizontal, or with another line or surface. 2. One of the orbital elements (parameters) that specifies the orientation of an orbit. It is the angle between the orbital plane and a reference plane, the plane of the celestial equator for geocentric orbits and the ecliptic for heliocentric orbits.

HYPOTENUSE
The side of a plane right triangle opposite the right angle; the longest side of a plane right triangle

FORCE PUMP
A device used to inject a solution into a closed system through an opening such as a drain valve.

FACE AREA
The total plane area of the portion of a grille, coil, or other items bounded by a line tangent
