Answer:
1: Angles in a triangle add up to 180°. The square represents a right angle (90°)
[tex]x=180-90-60=30[/tex]
2:
[tex]y=180-100-45=35[/tex]
3:
Angles on a straight line add up to 180°.
[tex]x=180-70=110[/tex]
4:
[tex]y=180-120=60[/tex]
