Odpowiedzi

2009-12-09T18:12:32+01:00
I bok = x = 5,5
II bok = 4x = 5,5*4= 22

x+4x=27,5
5x=27,5
x=27.5:5
x=5,5

Ob= 2*5,5+2*22= 55

P= 5,5*22= 121cm = 12,1 dcm (kwadratowych)



2009-12-09T18:13:43+01:00
55÷2=27.5
27.5÷5=5.5
5.5×4=22.5

1bok -> 5.5cm
2bok -> 22.5cm

5.5cm=0.55dm
22.5cm=2.25dm

P=a×b
P=0.55dm×2.25dm=0.6875dm² (68.75cm)
2009-12-09T18:22:20+01:00
Bok a = x = 5,5cm
bok b = 4x = 4 * 5,5 = 22cm
Ob = 55cm

Ob = 2a + 2b
Ob = 2x + 2 * 4x
Ob = 10x
55 = 10x/:10
5,5 = x

P = a * b = 5,5 * 22 = 121cm² = 1,21dm²

Odp. Pole tego prostokąta ma 1,21 dm².