Question

perimetrul unui dreptunghi este de 20 cm. Afla laturile stiind ca 2 lungimi egat cu 3 latimi.

Answer 1

2L=3l
P ABCD = 2 L + 2 l
20 cm = 3 l + 2 l
5 l = 20 cm
l = 20:5
l = 4 cm
2 L = 3 l => 2 L = 3 x 4 => 2 L = 12 cm
L = 12:2 => L = 6 cm
Verificare: P ABCD = 20 cm
2 L + 2 l = 20 cm
2x6 + 2x4=20 cm
12 + 8 = 20
20 cm = 20 cm

Answer 2

2L=3l
P ABCD = 2 L + 2 l
20 cm = 3 l + 2 l
5 l = 20 cm
l = 20:5
l = 4 cm
2 L = 3 l => 2 L = 3 x 4 => 2 L = 12 cm
L = 12:2 => L = 6 cm
Verificare: P ABCD = 20 cm
2 L + 2 l = 20 cm
2x6 + 2x4=20 cm
12 + 8 = 20
20 cm = 20 cm