Respuesta :

Step-by-step explanation:

well, there are a few things you have to burn into your brain for all times. one of these is : the sum of all angles in a triangle is always 180 degrees. it does not matter what type of triangle it is. the sum is always 180 degrees.

so,

180 = A + 80 + 40

60 degrees = A

so, B. is the right answer.