Explanation:
Angle 1: (I solved this one last) 69 degrees :) . Because Angle 2 is 37 and we know the other existing angle is 74 we can do 74+37 and subtract that from 180.
Angle 2: 37 degrees. Because Angle 2 and the 53 degree angle add up to a right triangle (90 degrees) you can subtract 90-53 and get 37.
Angle 3: 106 degrees. Because the line is a straight line, all angles should add up to 180 degrees, and 180-74=106.
Angle 4: 21 degrees. Because we know that Angle 3 is 106 degrees, we can do (106+53) and then subtract from 180 because all angles in a triangle should equal 180 degrees.