Theseanglesare referredto as quadrantalbecauseeachangledefinesa quadrant.Noticethat withoutthe
arrowindicatingthe rotation, 270 olooksas if it is a 90o, definingthe fourthquadrant.Noticealso that 360o
wouldlook just like 0o. The differenceis in the actionof rotation.This idea of two anglesactuallybeingthe
sameangleis discussednext.
Coterminalangles
Considerthe angle 30
o
, in standardposition.