Answer:
Answer: (a). 290°
[tex]{ \tt{a + 40 \degree + 30\degree = 360\degree}} \\ \\ { \tt{a + 70\degree = 360\degree}} \\ \\ { \tt{a = 360\degree - 70\degree }} \\ \\ { \boxed{ \tt{ \: \: a = 290\degree}}}[/tex]
