solid angle

American  

noun

Geometry.

1. an angle formed by three or more planes intersecting in a common point or formed at the vertex of a cone.

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solid angle British  

noun

1. a geometric surface consisting of lines originating from a common point (the vertex) and passing through a closed curve or polygon: measured in steradians

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solid angle Scientific  

1. A three-dimensional angle, formed by three or more planes intersecting at a common point. Its magnitude is measured in steradians, a unitless measure. The corner of a room forms a solid angle, as does the apex of a cone; one can imagine an indefinite number of planes forming the smooth round surface of the cone all intersecting at the apex. Solid angles are commonly used in photometry.

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Etymology

Origin of solid angle

First recorded in 1695–1705

Example Sentences

Of two plaine angles a solid angle cannot be comprehended.

From The Way To Geometry by Bedwell, William

So Angulus Superficiarius, a superficiall Angle, is a surface consisting in the common section of two lines: So angulus solidus, a solid angle, in the common section of three surfaces at the least.

From The Way To Geometry by Bedwell, William

The normal section of the cone at that point is equal to dS cosθ, and the solid angle dω is equal to dS cosθ / x�.

From Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 3 "Electrostatics" to "Engis" by Various

Brianchon’s Theorem.—If a solid angle of six edges be circumscribed about a cone of the second order, then the planes through opposite edges meet in a line.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" by Various

A similar difference exists between a solid angle and an n-edge or an n-flat.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" by Various