x+y=2/3*180
x+y=120
x=1/3y
1/3y+y=120
x=1/3y
y+3y=360
x=1/3y
4y=360
x=1/3y
y=360/4
x=1/3y
y=90
x=90/3
y=90° masura al doilea unghi;
x=30° masura primului unghi:
Verificam:
x°+y°=120°⇒30°+90°=120°⇒120°=120°;
x°=1/3y°⇒30°=1/3*90°⇒30°=30°.
Desenul il faci tu.
Bafta!