Question

Calcutati in doua moduri perimetrul dreptunghiului care are:
a) lungimea de 9 cm si latimea de 6 cm;
b) latimea de 14 cm, iar lungimea cu 8 cm mai mare;
e) lungimea de 6 dm, iar latimea de 5 ori mai mică.​

Answer 1

Răspuns:

a)9+9+6+6=30

9×2+6×2=30

b)14+8=22(lungimea)

14+14+22+22=72

14×2+22×2=72

c)6dm=60 cm

60÷5=12cm

60+60+12+12=144

60×2+12×2=144

Answer 2

Răspuns:

P-perimetru

L-lungime

l-latime

a) I

P= 2×L+2×l

P =2×9+2×6

P=18+12=30 cm

II

P=2(L+l)= 2×(9+6)=2×15=30cm

P=30cm

b) L=l+8=14+8=22

P=2×22+2×14=44+28=72cm

P=2×(14+22)=2×36=72

c) l=L×5=6×5=30

P=2×6+2×30=12+60=72

P=2×(6+30)=2×36=72