Răspuns :
l = 2/3 * L
P = 180
180 = 2 * 2 L/3 + 2 L
180 = 4 L/3 + 2 L
540 = 4 L + 6 L
L = 540 : 10
L = 54 m
l = 54 * 2/3
l = 36 m
P = 180
180 = 2 * 2 L/3 + 2 L
180 = 4 L/3 + 2 L
540 = 4 L + 6 L
L = 540 : 10
L = 54 m
l = 54 * 2/3
l = 36 m
[tex]P=2\cdot(L+l)=180m\;\;\Leftrightarrow\;;\;L+l=180=90\;\\ Stiim\;ca\;\;l\;=\;\frac{2}{3}\cdot{L}\\
inseamna\;ca\;\frac{l}{2}=\frac{L}{3}=\frac{90}{5}=18\;;\\
l=2\cdot18=36(m)\;\;;\;\;L=3\cdot18=54(m)\;;[/tex]