NP=3PB => PB = NP:3 = 18:3 = 6 cm => NB =12cm
AN=2AM
MN = AN+AM = 2AM+AM = 3AM => AM=MN:3=15:3 = 5cm => AN=10cm
se observa urmatoarea egalitate:
[tex] \frac{AN}{NM}= \frac{NB}{NP} \\ \frac{10}{15} = \frac{12}{18} \\ \frac{2}{3} = \frac{2}{3} [/tex]
Aceasta inseamna ca AB|| MP inseamna ca este adevarata relatia:
[tex] \frac{NB}{NP} = \frac{AB}{MP} \\ \frac{2}{3} = \frac{AB}{21} => AB = 21*2:3 = 14cm[/tex]
Perimetrul triunghiului ABN = AB+AN+NB = 14+10+12 = 36cm
