Answer:
See below
Step-by-step explanation:
Use triangle on the right to find x
x + 100 + 60 = 180
( since all of the interior angles of a triangle sum to 180)
then x = 20°
Use left triangle to find y
55 + 80 + y = 180
y = 45°
then use the small middle triangle to find z
x + y + z = 180
45 + 20 + z = 180 z = 115 °
