Matematika - vypočítej obvod těchto obdélníků:
a) a = 4 cm; b = 3 cm
b) a = 21 cm; b = 15 cm
c) a = 19 m; b = 30 m
d) a = 25 mm; b = 31 mm
e) a = 5 m; b = 70 dm
f) a = 40 mm; b = 8 cm
Vzor:
a) o = 2 . (a + b)
o = 2 . (4 + 3)
o = 2 . 7
o = 14 cm
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