In geometry, a **solid angle** (symbol: **Ω**) is the two-dimensional angle in three-dimensional space that an object subtends at a point. It is a measure of how large the object appears to an observer looking from that point. In the International System of Units (SI), a solid angle is a dimensionless unit of measurement called a **steradian** (symbol: **sr**).

A small object nearby may subtend the same solid angle as a larger object farther away. For example, although the Moon is much smaller than the Sun, it is also much closer to Earth. Therefore, as viewed from any point on Earth, both objects have approximately the same solid angle as well as apparent size. This is most easily observed during a solar eclipse.

Read more about Solid Angle: Definition and Properties, Practical Applications, Solid Angles in Arbitrary Dimensions

### Other articles related to "angle, solid angle, solid angles":

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**Solid Angle**s in Arbitrary Dimensions

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### Famous quotes containing the words angle and/or solid:

“Modesty is the only sure bait when you *angle* for praise.”

—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)

“London ... remains a man’s city where New York is chiefly a woman’s. London has whole streets that cater to men’s wants. It has its great *solid* phalanx of fortress clubs.”

—Louis Kronenberger (1904–1980)