en.wikipedia.org/wiki/Vertical_plane

Vertical plane is used in radio to plot an antenna's relative field strength perpendicular to the ground on a polar graph. Normally the maximum of 1.000 or 0 dB is ...

en.wikipedia.org/wiki/Horizontal_and_vertical

The usage of the inter-related terms horizontal and vertical as well as their symmetries and ... a) Through any point P in the plane, there is one and only one vertical line within the plane and one and only one horizontal line within the plane.

www.merriam-webster.com/dictionary/vertical+plane

Define vertical plane: a plane that passes through a vertical line.

medical-dictionary.thefreedictionary.com/vertical+plane

1. a flat surface determined by the position of three points in space. 2. an imaginary flat surface that divides the body into sections (see accompanying figure).

www.thefreedictionary.com/Vertical+plane

(Conic Sections), A plane passing through the vertex of a cone, and through its axis. (Projections), Any plane which passes through a vertical line. (Persp.) ...

www.amazon.com/Vertical-Plane-Ken-Webster/dp/0586204768

Amazon.com: The Vertical Plane (9780586204764): Ken Webster: Books.

www.unexplained-mysteries.com/forum/topic/9878-the-vertical-plane

For years I have been searching out a book called 'The Vertical Plane'. It's an acount of a very unusual haunting that took place in Cheshire in ...

www.adlerpedia.org/concepts/70

The terms horizontal and vertical planes of movement were introduced by Lydia Sicher in a paper presented at the 1954 Annual Meeting of the American Society ...