## perpendicular Quick reference

### The Concise Oxford Dictionary of Mathematics (5 ed.)

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

## perpendicular bisector Quick reference

### The Concise Oxford Dictionary of Mathematics (5 ed.)

... bisector The perpendicular bisector of a line segment AB is the straight line perpendicular to AB through the midpoint of AB...

## perpendicular planes Quick reference

### The Concise Oxford Dictionary of Mathematics (5 ed.)

... planes Two planes in 3‐dimensional space are perpendicular if normals to the two planes are perpendicular. If n 1 and n 2 are vectors normal to the planes, this is so if n 1 . n 2...

## common perpendicular Quick reference

### The Concise Oxford Dictionary of Mathematics (5 ed.)

...perpendicular 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...

## perpendicular distance Quick reference

### The Concise Oxford Dictionary of Mathematics (5 ed.)

... distance The distance from a point to a line or plane measured along the line perpendicular to the line or plane which passes through the given point. It will be the shortest distance between the point and any given point on the line or...

## perpendicular lines Quick reference

### The Concise Oxford Dictionary of Mathematics (5 ed.)

... 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...

## perpendicular axis theorem Quick reference

### The Concise Oxford Dictionary of Mathematics (5 ed.)

... axis theorem The following theorem about moments of inertia of a lamina : Theorem Suppose that a rigid body is in the form of a lamina lying in the plane z =0. Let I 0x , I 0y and I 0z be the moments of inertia of the body about the three coordinate axes. Then I 0z = I 0x + I 0y...

## perpendicular

## common perpendicular

## perpendicular bisector

## perpendicular planes

## perpendicular distance

## perpendicular lines

## Perpendicular Axis Theorem

## equinoctial Quick reference

### A Dictionary of Weights, Measures, and Units

...Relating to an equinox, i.e. one of the two points in the year when Earth's axis is perpendicular to the direction of the Sun, making day and night equal in length. For equinoctial year see year...

## foot⋅pound Quick reference

### A Dictionary of Weights, Measures, and Units

...form is the foot⋅poundal .) The composite name punctuated by a hyphen is misleading. The pound⋅foot , although having the same units and thereby interchangeable with foot⋅pound, is preferably used distinctively for torque. With torque, the applicable foot is measured perpendicular to the line of the force; with work it is along that...

## candela Quick reference

### A Dictionary of Weights, Measures, and Units

...the temperature of solidification of platinum is 60 new candles per square centimetre’. 1948 9th CGPM ‘candela’ adopted in place of (new) candle. 1967–68 13th CGPM: ‘ decides to express the definition of the candela as follows: The candela is the luminous intensity, in the perpendicular direction, of a surface of 1/600000 square metre of a black body at the temperature of freezing platinum under a pressure of 101 325 newtons per square metre’. 1979 16th CGPM: ‘ decides 1. The candela is the luminous intensity, in a given direction, of a source that emits...

## normal ((to a plane)) Quick reference

### The Concise Oxford Dictionary of Mathematics (5 ed.)

... (to a plane) A line perpendicular to the plane. A normal is perpendicular to any line that lies in the...

## shearing force ((mechanics)) Quick reference

### The Concise Oxford Dictionary of Mathematics (5 ed.)

...force (mechanics) The internal force perpendicular to the axis of a thin rod or...

## normal vector ((to a plane)) Quick reference

### The Concise Oxford Dictionary of Mathematics (5 ed.)

...vector (to a plane) A vector whose direction is perpendicular to the plane. A normal vector is perpendicular to any vector whose direction lies in the...