Answer:
its 100
Step-by-step explanation:
well since its a parallel line, 7 and 3 are corresponding and that makes 3 also 80. buh then 3 is also adjacent to 2 and that makes it also 80 and since 2 is on the same line as 1 and an angle on a straight line is 180, it automatically makes 1 an angle of 100 as 180 - 80 should give u 100.
