Question

lungimile laturile unui triunghi sunt direct proportionale cu 3,5,7, iar perimetrul său este 360cm. Aflati lungimeaacestor laturi

Answer 1

AB/3=AC/5=BC/7=k
AB/3=k  =>AB=3k
AC/5=k  =>AC=5k
BC/7=k  =>BC=7k

P=AB+AC+BC=360
=>3k+5k+7k=360
15k=360
k=360:15
k=24

=>AB=3k    AB=3X24=72
=>AC=5k   AC=5X24=120
=>BC=7k    BC=7X24=168

verificare
P=72+120+168=360

Answer 2

[tex] \frac{a}{3}= \frac{b}{5}= \frac{c}{7}=k \\ \\ a=3k, b=5k , c=7k \\ \\ a+b+c=360 \\ \\ 3k+5k+7k=360 , 15k=360, k=360:15 \\ \\ k=24 \\ \\ a=3k=24*3=72 \\ \\ b=5k=5*24=120 \\ \\ c=7k=7*24=168 \\ \\ [/tex]

a=72, b=120 si c=168

verificare
a+b+c=360⇒72+120+168=360⇒360=360