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

But plaine angles making a solid angle, are lesser than foure right angles, by the 8 e xxij.

From The Way To Geometry by Bedwell, William

Definition.—The solid angle subtended by any surface at a point is measured by the quotient of its apparent surface by the square of its distance from that point.

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

At all events, it has the advantage of communicating directly with both the rivers, by whose junction the Sungum, or solid angle, is formed.

From The Lieutenant and Commander Being Autobigraphical Sketches of His Own Career, from Fragments of Voyages and Travels by Hall, Basil