Odpowiedzi

2009-11-12T17:42:14+01:00
1. Obw= 14 π
l= 2 πr
r= 7
p koła = πr²
p= 49 π
49 * 22/7 =84 -> wynik dokładny

drugiego nie wiem

1 5 1
2009-11-12T17:46:40+01:00
1.
Obw = 2 π r
14π = 2 π r / ÷2
7 = r
P = π r²
P = 22/7 * 7² = 154 cm

2.
d₁ = 14 cm , r₁ = 7 cm
P₁ = π r²
P₁ = 49 π

P₂ = π r²
P₂ = π 3² = 9π

P₃ = 49 π - 9 π = 40 π = 40* 3,14 = 125,6 cm²
3 5 3
2009-11-12T17:54:26+01:00
1) L=2πr
P=πr²
L=14πcm
π=22/7
14π=2πr
2πr=14π / 2π
r=7cm

P=πr²= 22/7 × 7² =22/7 × 49 = 154 cm²



2)l1=14
π=3,14
P=πr²
r₁ = 7 cm
P₁ = π r²
P₁ = 49 π

P₂ = π×r²
P₂ = π ×3² = 9π

P₃ = 49× π - 9 ×π = 40× π = 40×3,14 = 125,6 cm²
2 5 2