Respuesta :

Answer:

d

Step-by-step explanation:

all of the angles add up to equal 180 so we setup the equation as 45+3x=180

first you subtract each side by 45

135=3x

then you divide each side by 3 and get that

x=45

Answer:

D, 45°

Step-by-step explanation:

at [tex]x=45[/tex]

the resulting angles would be [tex]45, 90, 45[/tex] and these add up to [tex]180[/tex]°