Glossary · A
Arithmetic mean
The number halfway between two others: (a + b)/2. For 6 and 12 it is 9.
See also: Geometric mean, Harmonic mean
Rules that use the word
The three means. Between two numbers a and b, find the arithmetic mean (a + b)/2, the geometric mean √(ab) and the harmonic mean 2ab/(a + b); use them to find a third dimension that belongs to the other two.
Where it appears in the book
In the chapters Proportion and Number.
Nearby in the glossary
Arboretum · Arcade · Arch brace · Architrave · Arris · Ashlar · Astragal · Atrium