Explanation:
Since angle 1 is on a straight line and we know that angle 4 is 160, and a straight line has a sum of 180 degrees, simply subtract 160 from 180 to get angle 1.
Angle one would be 180-160 = 20
Since the sum of angles in a triangle is 180 and we already know 2 of them, angle 1 is 20 and angle 3 is 30, just add them together and then subtract that from 180. 20 + 30 = 50, and 180 - 50 = 130.
So in conclusion:
Angle 1 is: 20
Angle 2 is: 130