Odpowiedź:
a) 4 m x 7 m x 2 m
a= 4 m b=7 m c=2 m
Pc= 2(ab+ac+bc)
Pc= 2(4m*7m+4m*2m+7m*2m)
Pc= 2( 28m²+8m²+14m²)
Pc= 56m²+16m²+28m²
Pc= 100 m²
b) 2 cm x 4,5 cm x 3,5 cm
a= 2 cm
b= 4,5 cm
c= 3,5 cm
Pc= 2(ab+ac+bc)
Pc= 2(2cm*4,5cm+2cm*3,5cm+4,5*3,5cm)
Pc= 2( 9cm²+7cm²+ 15,75cm²)
Pc= 18cm²+14cm²+31,5cm²
Pc= 63,5 cm²
c) 11 dm x 11 dm x 11 dm
a= 11 dm
b= 11 dm
c= 11 dm
Pc= 2(ab+ac+bc)
Pc= 2( 11dm*11dm+11dm*11dm+11dm*11dm)
Pc= 2(121dm²+121dm²+121dm²)
Pc= 2*363dm²
Pc= 726 dm²
d) 25 mm x 4,7 cm x 0,2 dm
1 mm= 0,1 cm
1 dm= 10 cm
25 mm= 25*0,1= 2,5 cm
0,2 dm= 0,2*10 = 2 cm
a= 2,5 cm b= 4,7 cm c = 2cm
Pc= 2(ab+ac+bc)
Pc= 2(2,5cm*4,7cm+2,5cm*2cm+4,7cm*2cm)
Pc= 2( 11,75 cm²+5 cm²+9,4cm²)
Pc = 2*26,15 cm²
Pc= 52,3 cm²
