## Trigonometry 7th Edition

Complement of $120^{\circ}$ = - $30^{\circ}$ Supplement of $120^{\circ}$ = $60^{\circ}$
Complement of $120^{\circ}$ = $90^{\circ} - 120^{\circ}$ = - $30^{\circ}$ (As sum of the measures of complementary angles is 90 degrees, we can find 'one' by subtracting 'other' from $90^{\circ}$ ) Supplement of $120^{\circ}$ = $180^{\circ} - 120^{\circ}$ = $60^{\circ}$ (As sum of the measures of supplementary angles is 180 degrees, we can find 'one' by subtracting 'other' from $180^{\circ}$)