Answer:
Cosine
Step-by-step explanation:
SohCahToa
The sides are: adjacent to the angle and are the hypotenuse.
(hope this helps :P)
x = 60.
Vertical angles are congruent so
x + 20 = 80
x = 80 - 20 = 60.
Option 3)............... I guess so
Lol
Wdym?