4. m(A)+m(B)+m(C)=180
23+4m(C)+m(C)=180
23+5m(C)=180
5m(C)=180-23
5m(C)=157
m(C)=157:5=31,4
m(B)=4*31,4=125,6 (* inseamna inmultit)
m(A)=180-31,4-125,6=23
5. m(B)=2m(A)
m(C)=3m(A)
m(A)+m(B)+m(C)=180
m(A)+2m(A)+3m(A)=180
6m(A)=180
m(A)=180:6=30
m(B)=2*30=60
m(C)=3*30=90
6.Din m(A)+m(B)+m(C)=180 rezulta m(C)=180-54-86=40
b)unghiul exterior este egal cu m(A)+m(C)=54+40=94