Respuesta :

Vividerla
180 - 155 = 25

25 + 80 = 105

180 - 105 = 75

x = 75


Hope I helped!

Let me know if you need anything else!

~ Zoe (Rank:'Genius')
You know that the angle that is in the smaller triangle is supplementary to 155 because they are on the same line. So that angle is 25. 

You know that the sum of angles in a triangle is 180. 
So, x + 80 + 25 = 180
x + 105 = 180
x = 75 degress
Q&A Education