Question

perimetrul unui dreptunghi este 144m.aflati aria dreptunghiului stiind ca lungimea este:a)de trei ori mai mare decat latimea sa b)cu 14m mai mare decat latimea sa

Answer 1

P=2(L+l)=144
L+l=144:2=72 m
a)
L=3l
3l+l=72 m
4l=72 m
l=18 m
L=18×3=54 m
A=L×l=54×18=972 m²

a)
L=l+14
l+14+l=72 m
2l=58 m
l=29 m
L=29+14=43 m
A=L×l=43×29=1247 m²

Answer 2

P=2(L+l)
a) L=3l
2(3l+l)=144 m
4l=144 m/2
4l=72 m
l=72 cm/4
l=18 m=>L=3*18 m=54 m
A=L*l=54 m*18 m=972 m^2

b) L=l+14 m
2(l+14 m+l)=144 m
2l+14 m=144 m/2
2(l+7 m)=72 m
l+7 m=72 m/2
l+7 m=36 m
l=36 m-7 m
l=29 m=L=29 cm+14 m=43 m
A=L*l=43 m*29 m=1247 m^2