... lines In coordinate geometry of the plane, a useful necessary and sufficient condition that two lines, with gradients m 1 and m 2 , are perpendicular is that m 1 m 2 =−1. (This is taken to include the cases when m 1 =0 and m 2 is infinite, and vice...

In coordinate geometry of the plane, a useful necessary and sufficient condition that two lines, with gradients m 1 and m 2, are perpendicular is that m 1 m 2=−1. (This is taken to include the cases ...

*David Hey*

...years of the 14th century until the Reformation and later a native style known as Perpendicular Gothic was developed. This is named after the perpendicular lines of the mullions in the windows (which were enlarged until they filled all the available space in the walls), but the style includes much more than that, e.g. flat lead roofs hidden behind battlements and pinnacles, long ranges of clerestory windows, and carved wooden roofs. See John Harvey , The Perpendicular Style, 1330–1485 (1978). In Ireland, Scotland, and Wales there are far fewer...

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10 Paper
Reference library

...measuring the existing trimmed sheet. First, a book’s gathering that corresponds to a single sheet needs to be identified; the orientation of chain lines in bound, laid paper helps determine this ( see format ). In a sheet folded in half, the chain lines run parallel to the fold and book spine, producing a *folio . A second fold, perpendicular to the first, will produce chain lines running perpendicular to the spine, and thus a *quarto . A third fold restores the original orientation, producing an *octavo , and so on. Once a single sheet has been...

Let l 1 and l 2 be two straight lines in space that do not intersect and are not parallel. The common perpendicular of l 1 and l 2 is the straight line that meets both lines and is perpendicular to ...

At right angles to one another. Can be of two lines, two planes, a line and a plane, or a line and a surface.

Imaginary lines in a field of force that enable the direction and strength of the field to be visualized. They are used primarily in electric and magnetic fields; in electric fields they are ...

In laid paper, wire-lines are the light, close-set parallel lines, just visible when held up to the light, that run perpendicular to the more pronounced chain-lines (Compare chain-lines). They are ...

(in 3-dimensional space)Let l 1 and l 2 be lines in space that do not intersect. There are two cases. If l 1 and l 2 are parallel, the distance between the two lines is the length of any line segment ...

In laid paper, faint lines—perceptible when the sheet is held up to the light—running close together and perpendicular to the chain lines. In hand-made paper, they are created by the ...

1 (line) The two-dimensional locus of all points with equal value for a potential field.2 (surface) The three-dimensional distribution of all points of equal value for a potential field. ...

Paper printed with intersecting lines for drawing graphs or diagrams. The simplest form has equally spaced perpendicular lines, but one or both axis may use logarithmic scales, or scales derived from ...

A pair of intersecting lines, to be taken, for example, as coordinate axes, are oblique if they are not (or at least not necessarily) perpendicular. Three concurrent lines, similarly, are oblique if ...

A method of assessing the angulation and extent of impaction of mandibular third molars, first described by G. B. Winter in 1926. A line drawn along the occlusal surfaces of the erupted mandibular ...

Shorthand for ‘et’/‘and’, deriving from Cicero’s servant Marcus Tullius Tiro’s Tironian notes. Beginning as two perpendicular lines of equal length (┐), it developed into ‘7’. Tironian ‘et’ was used ...

Let P be a point on a smooth surface. The tangent at P to any curve through P on the surface is called a tangent line at P, and the tangent lines are all perpendicular to a line through P called the ...

A class of iron meteorite, containing not more than 4–6% nickel. Hexahedrites consist of large cubic crystals of kamacite (an iron–nickel alloy) over 50 mm across, and they can be cleaved in three ...

In elementary work, a cylinder, if taken, say, with its axis vertical, would be reckoned to consist of a circular base, a circular top of the same size, and the curved surface formed by the vertical ...

Let Ox, Oy and Oz be three mutually perpendicular directed lines, intersecting at the point O. In the order Ox, Oy, Oz, they form a right-handed system if a person standing with their head in the ...

The double perpendicular line marking the end of a comp. or of some section thereof. (It may or may not coincide with a single bar line and if it does not do so has no rhythmic function.) Usually ...