Odpowiedź:
a = 2dm
b =40cm =4dm
h =700 mm = 70cm = 7dm
Pc = 2ab +2ah +2bh = 2*2*4 + 2*2*7+2*4*7 = 16 + 28 + 56 = 100 dm²
Szczegółowe wyjaśnienie:
1dm =10 cm = 100 mm
Hej!
[tex]P_c=2\cdot(ab+bc+ac)\\\\a=2 \ dm\\\\b=40 \ cm=4 \ dm\\\\c=700 \ mm=70 \ cm=7 \ dm\\\\P_c=2\cdot(2\cdot4+4\cdot7+2\cdot7)\\\\P_c=2\cdot(8+28+14)=2\cdot50=\boxed{100 \ dm^2}[/tex]