Question

find x,y,z solution of the problem

Answer 1

y=120 degree (opposite angle to the other 120 degree)
x = Z (opposite angles)
x=360-2(120)/2
ie x=120/2=60
x=z=60
y=120

Answer 2

x+y+z+120=360
2x+z+120=360
2x+z=360-120
2x+z=240
x+z=240/2
x+z=120
therefore x+y=120
120-240=z
120=z
120=x+y
120=2x
x=120/2
x=60
therefore x+y =120
so,x=60,y=60
therefore x+y+z+120=360
60+60+120+120=360
Hence proved