Obliczenia:
Obwód = 4*1cm = 4cm
Obwód = 4a
8cm = 4a
4a = 8cm /:4
a = 2cm
Obwód = 4*(4cm 5mm) = 16 cm 20 mm = 18 cm
Obwód = 4a
24 cm = 4a
4a = 24cm /:4
a = 6cm
Obwód = 2*12cm + 2*5cm = 24cm + 10cm = 34 cm
Obwód = 2a + 2b
28cm = 2*8cm + 2b
28cm = 16cm + 2b
28cm - 16cm = 2b
12cm = 2b
2b = 12cm /:2
b = 6cm
Obwód = 2a + 2b
26cm = 2a + 2*6cm
26cm = 2a + 12cm
26cm - 12cm = 2a
14cm = 2a
2a = 14cm /:2
a = 7 cm
Obwód = 2a + 2b
17cm = 2*(5cm 5mm) + 2b
17cm = 10cm 10 mm + 2b
17cm = 11 cm + 2b
17cm - 11cm = 2b
6cm = 2b
2b = 6cm /:2
b = 3cm
