By definition, 1 is the magnitude, absolute value, or norm of a unit complex number, unit vector, and a unit matrix (more usually called an identity matrix).
Manut teges, 1 inggih punika besaran, pikolih mutlak, utawi norma saking wilangan kompleks satuan, vektor satuan, miwah matriks satuan (ketah kabaos matriks identitas).