## Trigonometry 7th Edition

$30^{\circ}$
Complement of $60^{\circ}$ will be another angle that terminal side needs to sweep in order to reach position y i.e. standard position of $90^{\circ}$. Obviously it will be $30^{\circ}$. Another way to find complement of an angle will be to subtract it from $90^{\circ}$. Hence complement of $60^{\circ}$ = $90^{\circ}$- $60^{\circ}$ = $30^{\circ}$