Answer
a)$60^{\circ}$
b)$150^{\circ}$
Work Step by Step
a) Formula to find Complement of an angle: $90^{\circ}$ - $X^{\circ}$
$90^{\circ}$ - $30^{\circ}$ = $60^{\circ}$
b) Formula to find Supplement of an angle: $180^{\circ}$ - $X^{\circ}$
$180^{\circ}$ - $30^{\circ}$ = $150^{\circ}$