14. You would only need to know 1 because two vertical angles have the same value. Also since angles 1&2 create a straight line, you can subtract angle 1 from 180º to find the measurement of angle 2. On top of that, angles 1&2 and angles 5&6 are the same.
15. 5=119º 1=61º 2=119º 3=61º 4=119º 6=61º 7=119º same reasoning as 14.
18. 56º. Angle 4 and angle 5 are the same, so you can take the value from angle 1 and subtract it from 180º to find the answer.