Respuesta :

Given:

∠STU = 8x 
∠RST = (7x – 54) 

Solution:
∠SRT + ∠RST = 8x (exterior angle is sum of interior angles) 
∠SRT + (7x – 54) = 8x 
∠SRT = 8x – (7x – 54) 
= x + 54 


∠STR + ∠STU = 180 is the linear pair 


x + 54 + 8x = 180 


9x = 126 


x = 14