Step-by-step explanation:
[tex] m \angle \: a + 80 \degree = 180 \degree \\ (linear \: pair \: \angle s) \\ \therefore \: a = 180 \degree - 80 \degree \\ \huge \red { \boxed{\therefore \: a = 100 \degree}} \\ \\ \huge \purple { \boxed{m \angle \: b = 80 \degree }} \\ (corresponding \: \angle s) \\ \\ m \angle \: c=m \angle \: a \\ (vertical \: \angle s) \\\huge \orange { \boxed{ \therefore \: m \angle \: c = 100 \degree}}[/tex]
