in loc de masura unghi am sa scriu direct A, B sau C dupa caz ca nu stiu cum sa pun masuri aici
deci
A+B+C=180 grade
A=2B⇒2B+B+C=180 grade
3B+C=180 grade
C-B=48 grade⇒C=48 grade+B
3B+48 grade+B=180 grade
4B+48grade=180 grade
4B=180-48 grade
4B=132 grade
B=132:4grade⇒B=33grade
A=2B⇒A=2*33⇒A=66grade
C=48+B⇒C=48+33⇒81 grade