Respuesta :

Answer:

[tex]m\angle B = 28^{\circ}[/tex]

Step-by-step explanation:

All angles in a triangle must add up to [tex]180^{\circ}[/tex]

We can solve for [tex]\angle B[/tex] using this knowledge

[tex]\angle B + 40 + 112 = 180\\\angle B + 152 = 180\\\boxed{\angle B = 28}[/tex]

That is the answer

- Kan Academy Advance

Since all the angles of a triangle combined equal 180, add the given degrees and did subtract them from 180.

40+112=152
180-152=28
B=28