Question

find x and y if a triangle angle z is 120degree

Answer 1

the sum of all angles of a triangle is 180. So,
x+y+z=180.
x+y+120=180.
x+y=60
x=30
and
y=30

Answer 2

sum of all side of the triangle is 180°
z=120°
x+y+z=180°
x+y+120=180°
x+y=180°-120°
x+y=60°
let y also be x
x+x=60°
2x=60°
x=60/2
x=30°

x=30°
y=30°
z=120°