Pls answer this It will help me understand this question

r:-
[tex]\\ \rm\hookrightarrow r+60+50=180[/tex](Supplementary)
[tex]\\ \rm\hookrightarrow r+110=180[/tex]
[tex]\\ \rm\hookrightarrow r=180-110[/tex]
[tex]\\ \rm\hookrightarrow r=70[/tex]
[tex]\\ \rm\hookrightarrow p=50(Opposite\: angles)[/tex]
q:-
[tex]\\ \rm\hookrightarrow q=70+60(Opposite \:angles)[/tex]
[tex]\\ \rm\hookrightarrow q=130[/tex]
Answer:
[tex]{ \sf{60 \degree + r + 50\degree = 180\degree}} \\ { \sf{ \{angles \: on \: straight \: line \}}} \\ { \sf{r + 110\degree = 180\degree}} \\ { \underline{ \sf{r = 70\degree}}}[/tex]
[tex]{ \sf{q + 50\degree = 180\degree}} \\ { \sf{ \{angles \: on \: straight \: line \}}} \\ { \sf{q = 180\degree - 50\degree}} \\ { \underline{ \sf{q = 130\degree}}}[/tex]
[tex]{ \sf{p + q = 180\degree}} \\ { \sf{ \{angles \: on \: straight \: line \}}} \\ { \sf{p + 130\degree = 180\degree}} \\ { \sf{ \underline{p = 50\degree}}}[/tex]
or:
[tex]{ \underline{ \sf{p = 50\degree \: \{alternate \: angles \}}}}[/tex]