SI Measurement of Solid Angle, Symbol Sr
Puzzle 15 of Halloween Movies Medium Pack
Question is: SI Measurement of Solid Angle, Symbol Sr
and the answer is: STERADIAN
Word Meaning:
STERADIAN — (geometry) In the International System of Units, the derived unit of solid angle; the solid angle subtended at the centre of a sphere of radius r by a portion of the surface of the sphere that has area r². Symbol: sr
Definitions from Wiktionary.