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.

---

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

---

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.

---

Etymology

Origin of solid angle

First recorded in 1695–1705

Example Sentences

This appeareth plainely out of the nature of a solid angle, by the kindes of plaine figures.

From The Way To Geometry by Bedwell, William

Three regular polygons of six or more sides cannot form a solid angle.

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

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

A solid angle is definable as the space contained by three or more planes intersecting in a common point; it is familiarly represented by a corner.

From Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1 by Various

The second solid is composed of the same triangles, which unite as eight equilateral triangles, and make one solid angle out of four plane angles—six of these angles form a regular octahedron.

From Timaeus by Jowett, Benjamin