#5 = 53° #7 = 125° #6 = 55° #2 = 72° #3 = 55° #1 = 53° #4 = 127°
triangle = 180° 
alternating interior angles are the same (#6 & #3 and #5 and #1) 
#3 and #7 should equal 180° 
#1 and #4 should also equal 180° 
#6 and #7 should equal 180° 
#4 and #5 should equal 180°