The steradian (symbol: sr) or square radian[1][2] is the unit of solid angle in the International System of Units (SI). It is used in three-dimensional geometry, and is analogous to the radian, which quantifies …

Since a radian is (180/ π) degrees, we can square this to find that a steradian is (180/ π) 2 ≈ 3282.8 square degrees. The Moon's angular diameter is about 0.5°, so it covers: That is a tiny fraction of the …

What is a Steradian in Maths? The steradian or square radian is the SI unit of solid angular measure. The symbol used to represent steradian is ‘sr’. It is used to measure two-dimensional angular span in …

steradian, unit of solid-angle measure in the International System of Units (SI), defined as the solid angle of a sphere subtended by a portion of the surface whose area is equal to the square of the sphere’s …

Dec 3, 2025 · Geometry Trigonometry Spherical Trigonometry Steradian The unit of solid angle. The solid angle corresponding to all of space being subtended is steradians.

The steradian, symbol sr, is the SI coherent derived unit for solid angle. One steradian is defined as the solid angle subtended at the centre of a unit sphere by a unit area of its surface. For a sphere of …

A steradian can be defined as the solid angle subtended at the centre of a unit sphere by a unit area (of any shape) on its surface. For a general sphere of radius r, any portion of its surface with area A = r2 …

The steradian (symbol: sr) or square radian is the SI unit for solid angle. It is defined as the solid angle that, when projected onto a surrounding spherical surface, produces an area (of any shape) equal to …

The steradian (symbol: sr) is the SI unit of solid angle. It is used to describe two-dimensional angular spans in three-dimensional space, analogous to the way in which the radian describes angles in a …

Feb 24, 2004 · The entire surface of a sphere subtends 4 π steradians. Symbol, sr. One steradian is approximately equal to 3,283 square degrees or 1.18 × 10⁷ square minutes or 4.25 × 10¹⁰ square …