Answer:
down below
Step-by-step explanation:
straight lines are 180 degrees and you have 2 angles on a line. one of which is 72 and the other is unknown. It is solved for below.
[tex]180=72+x\\180-72=72+x-72\\108=x[/tex]
your missing degree is 108.
i may not be right, if i'm not i am very sorry.
