Two angles, ∠1

Question

and ∠2
, in a diagram are supplementary. If m∠1=77°
, what equation can you write to solve for m∠2
? Let m∠2=x°
(1 point)
Responses

x°+77°=90°

x°=90°−77°

x°=77°

x°+77°=180°

Answer 1

x°+77°=180°