Proszę pomożesz ?...matma :(
polecenie brzmi :
1.oblicz przybliżone długości okręgów o promieniach: 2 cm, 4m , 0,3 cm , 10 km
2. oblicz przybliżone długości okręgów o średnicach : 2 cm, 3m,0,4cm,200m
3. oblicz przybliżone długości promieni kół o obwodach : 10 cm , 1 m , 628mm , 3,5 cm

3

Odpowiedzi

2009-11-08T13:34:26+01:00
L = 2πr

a)
l = 2 * 3,14 * 2cm = 12,56cm
l = 2 * 3,14 * 4m = 25,12m
l = 2 * 3,14 * 0,3cm = 1,89cm
l = 2 * 3,14 * 10km = 62,8km

d = 2r

b)
l = 2 * 3,14 * 1cm = 6,28cm
l = 2 * 3,14 * 1,5cm = 9,42cm
l = 2 * 3,14 * 0,2cm = 1,26cm
l = 2 * 3,14 * 100m = 628m

l = 2πr
r = l/2π

c)
r = 10cm/2 * 3,14 = 10cm / 6,28 = 1,6cm
r = 1m / 2 * 3,14 = 1m / 6,28 = 0,16m
r = 628mm / 2 * 3,14 = 628mm / 6,28 = 100mm
r = 3,5cm / 2 * 3,14 = 3,5cm / 6,28 = 0,56cm
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2009-11-08T13:39:55+01:00
1.
l = ? l = 2πr
r = 2cm
l = 2 * 3,14 * 2 = 4 * 3,14 = 12,56cm

r = 4m
l = 2 * 3,14 * 4 = 25,12m = 2512cm

r = 0,3cm
l = 2 * 3,14 * 0,3 = 1,884cm

r = 10km
l = 2 * 3,14 * 10 = 62,8km = 6280000cm

2.
l = ? l = dπ
d= 2cm
l = 2 * 3,14 = 6,28cm

d = 3cm
l = 3 * 3,14 = 9,42cm

d = 0,4cm
l = 0,4 * 3,14 = 1,256

d = 200m
l = 200 * 3,14 = 628m = 62800cm

3.
r = ? r = 1/2 d d = l/π
l = 10cm
d = 10/3,14 ≈ 3,18cm
r = 3,18/2 = 1,59cm

l = 1m
d = 100/3,14 ≈ 31,84m
r = 31,84/2 = 15,92m = 1592cm

l = 628mm
d = 628/3,14 ≈ 200mm
r = 200/2 = 100mm = 10cm

l = 3,5cm
d = 3,5/3,14 ≈ 1,12cm
r = 1,12/2 = 0,56cm
2009-11-08T13:42:51+01:00
1. l=2πr
π≈3,14
r=2cm; l=2*3,14*2cm=12,56cm
r=4m; l=2*3,14*4m=25,12m
r=0,3cm; l=2*3,14*0,3cm=1,884cm
r=10km; l=2*3,14*10km=62,8km

2.l=2πr
π≈3,14
d=2cm; r=1cm; l=2*3,14*1cm=6,28cm
d=3m; r=1,5m; l+2*3,14*1,5m=94,2m
d=0,4cm; r=0,2cm; l=2*3,14*0,2cm=1,256cm
d=200m; r=100m; l=2*3,14*100m=628m

3.l=2πr
π≈3,14
l=10cm; 10cm=2*3,14*r/6,28
r≈1,6cm
l=1m; 1m=2*3,14*r/6,28
r≈0,16m
l=628mm; 628mm=2*3,14*r/6,28
r=100mm
l=3,5cm; 3,5cm=2*3,14*r/6,28
r≈0,53cm

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