Respuesta :

2NS

Answer:

C

Step-by-step explanation:

The sum of the angles on a triangle must always equal 180 degrees. That means...

40 + 60 + (2n - 10) = 180

100 - 10 + 2n = 180

90 + 2n = 180

90 - 90 + 2n = 180 - 90

2n = 90

n = 45

I hope this helps!