Odpowiedź :
zad. 3
b) Ob = 2a + 2b
28 cm = 2 x 4 cm + 2b
28 cm = 8 cm + 2b |-8cm
20 cm = 2b |:2
b = 10 cm
zad. 4
Pole kwadratu:
P = a x a
P = 6m x 6m = 36 m²
Pole prostokąta:
P = a x b
P = 9 cm x 6 cm = 54 cm²
zad 3.
a) 9 (36 : 4 = 9)
b) 10cm ( 4 + 4 = 8, 28-8 = 20, 20: 2 = 10)
zad 4.
- 36 m (6 x 6 = 36)
- 54 cm (9 x 6 = 54)