Answer:
z=58
Step-by-step explanation:
Sum of interior angles of a n-gon = (n-2) 180
for this 7-gon (heptagon) (7-2)(180) = 900
so all of the angles added togehter = 900
z+50 + 2z + 2z+23 + 3z-37 + 2z+31 + 113 + 140 = 900
z = 58
