Question 193266
if  you  would  draw  a  rough  sketch
if  you  are  talking  about  consecutive  angles  around  one  intersection  of  transversal  and  parallel,  use  the  definition  of  a  straight  angle,  to  define  supplemental,  both  as  180 degrees.

if  you  are  looking  at  consecutive  for  two  parallel  lines,  you  might  have  to use  corresponding  as  equal,  and  then  straight,,,or  aia  and  then  straight  angles,,,,or  perhaps  even  vertical  angles,,,,and  then  corresponding  and  then  straight  angles.

just  pick  pair  you  want  to  be  supplimental,  and  then  go  to  other  parallel.

a  sketch  will  help  this  make  sense.