Respuesta :

Answer:

b = 60

Step-by-step explanation:

The sum of the angles of a triangle are 180

80+40+b = 180

Combine like terms

120+b =180

Subtract 120 from each side

b = 180-120

b = 60

Answer:

60°

Step-by-step explanation:

Recall that all triangles have an interior angle sum of 180. In other words:

[tex]\angle A+\angle B +\angle C = 180[/tex]

Plug in the angle values we know:

[tex](80)+(40)+\angle B = 180\\120+\angle B =180\\\angle B = 60\textdegree[/tex]