The lower-case letter φ is used as a symbol for:
The upper-case letter Φ is used as a symbol for:
See also other things named phi, Phi phenomenon.
... States Census Bureau, the town has a total area of 11.3 km² (4.4 mi²). 10.6 km² (4.1 mi²) of it is land and 0.6 km² (0.2 mi²) of it is ...