step 1
Find out the measure of angle 18
we have that
m<18=m<6 ------> by corresponding angles
m<6=37 degrees ----> given
so
m<18=37 degrees
step 2
Find out the measure of angle 19
we have that
m<19+m<18=180 degrees -------> by form a linear pair
so
m<19+37=180
m<19=143 degrees