Răspuns :
Notam L=lungimea si l- latimea
L=2l
P=2L+2l
2L+2l=54
Inlocuim:
4l+2l=54
6l=54
l= 9 cm
L=2l⇒L=18 cm
L=2l
P=2L+2l
2L+2l=54
Inlocuim:
4l+2l=54
6l=54
l= 9 cm
L=2l⇒L=18 cm
2xL+2xl=54 cm
L=2xl
2x2xl+2xl=54 cm
4xl+2xl=54 cm
6xl=54 cm
l=54 cm:6
l=9 cm
L=2x9 cm
L=18 cm
L=2xl
2x2xl+2xl=54 cm
4xl+2xl=54 cm
6xl=54 cm
l=54 cm:6
l=9 cm
L=2x9 cm
L=18 cm