Step-by-step explanation:
a)
Two of the three interior angles are known. Both are equal to 55°. This can be seen by looking closely at the picture. To find the third angle subtract the other two from 360°
[tex]360\textdegree-55\textdegree-55\textdegree=x[/tex]
b)
Do the same thing only afterward subtract the third angle from 180 to find the supplementary angle
[tex]360\textdegree-40\textdegree-28\textdegree=ans\textdegree\\180\textdegree-ans\textdegree=x[/tex]
