Prostokąt 1
P = 16cm^2
a = 8cm
b = 16 : 8 = 2cm
L = 8 * 2 + 2 * 2 = 20cm
2/20 = 1/10 = 10%
Prostokąt 2
P = 21cm^2
a = 7cm
b = 21 : 7 = 3cm
L = 7 * 2 + 3 * 2 = 20cm
3/20 = 15/100 = 15%
Prostokąt 3
P = 24cm^2
a = 6cm
b = 24 : 6 = 4cm
L = 6 * 2 + 4 * 2 = 20cm
4/20 = 20/100 = 20%
Odpowiedź: B