Răspuns :
Fa desenul si uite rezolvarea :
NM = AN+AM
AN + AM =15
Dar AN=2AM => 2AM+AM=15 => 3AM=15 => AM = 5 cm
AN=2*5=10 cm
NP=3BP => 18=3BP => BP=6 cm
NB=18-6=12 cm
NA / NM = NB/NP => 10/15=12/18=2/3
NA/NM=NB/NP (1)
Unghiul N - Unghi comun (2)
din 1 si 2 => Triunghiurile NAB si NMP sunt asemenea
=> NA/NM = AB/MP => 2/3 =AB/21 => AB =14
P ABN = 36 cm
NM = AN+AM
AN + AM =15
Dar AN=2AM => 2AM+AM=15 => 3AM=15 => AM = 5 cm
AN=2*5=10 cm
NP=3BP => 18=3BP => BP=6 cm
NB=18-6=12 cm
NA / NM = NB/NP => 10/15=12/18=2/3
NA/NM=NB/NP (1)
Unghiul N - Unghi comun (2)
din 1 si 2 => Triunghiurile NAB si NMP sunt asemenea
=> NA/NM = AB/MP => 2/3 =AB/21 => AB =14
P ABN = 36 cm
AN=2AM⇒ AN= 15:3*2= 10 cm
NP=3BP⇒NB= 18:3*2=12 cm
AB paralel cu MP ⇒ ⇔ ⇒ AB=(12*21)/18=14 cm
P= 14+10+12=36 cm