1)A+B+C=180 m(N)=m(P)
72+3B=180 m(M)=36
3B=108 =>180-36=144
B=36 m(N)=M(P)=144:2=72
C=2B
C=36∙2
C=72
3)MP II BC=>∆AMP≈∆ABC=>MP/BC=AM/AB=AP/AC
MN II AC=>∆MBN≈∆ABC=>MN/AC=BM/AB=BN/BC
MP/BC=AM/AB si MN/AC=BM/AB le adunam
MP/BC+MN/AC=AM/AB+BM/AB
AM/AB+BM/AB=(AM+BM)/AB=AB/AB=1
MP/BC+MN/AC=1