Unghiurile x si 2x sunt unghiuri externe de aceeasi parte a secantei
x+ 2x= 180 grade
3x= 180 grade
x=180 grade:3
x=60 grade
Deci unghiul x are masira de 60 grade si unghiul 2x are masura de 2 ori 60 grade=120 grade
y-40+ 2x=180 grade
Y-40+120=180 grade
Y+ 80=180 grade
Y= 180-80 grade
Y=100 grade
