$r=12\text{cm}$  

$d=2r=2\cdot 12\text{cm}=24\text{cm}$  

$O=2\pi r=\pi \cdot 2r=\pi \cdot 24\text{cm}=24\pi \text{cm}\approx 24\cdot 3,14{\text{cm}}^2=75,36{\text{cm}}^2$  

$P=\pi r^2=\pi \cdot {\left(12\text{cm}\right)}^2=\pi \cdot 144{\text{cm}}^2\approx 3,14\cdot 144{\text{cm}}^2=452,16{\text{cm}}^2$  

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$d=2r$   $2r=80\text{cm}\mid :2$  

$r=40\text{cm}$  

$O=2\pi r=2\pi \cdot 40\text{cm}=80\pi \text{cm}\approx 80\cdot 3,14\text{cm}=251,2\text{cm}$  

$P=\pi \cdot {\left(40\text{cm}\right)}^2=1600\pi \text{cm}=1600\cdot 3,14{\text{cm}}^2=5024{\text{cm}}^2$      

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$2\pi r=48\pi \text{cm}\mid :2\pi$  

$r=24\text{cm}$  

$d=2r=48\text{cm}$  

$O=2\pi r=\pi \cdot 2r=\pi \cdot 48\text{cm}=48\pi \text{cm}\approx 48\cdot 3,14\text{cm}=150,72\text{cm}$  

$P=\pi \cdot {\left(24\text{cm}\right)}^2=\pi \cdot 576{\text{cm}}^2=576\pi {\text{cm}}^2\approx 1808,64{\text{cm}}^2$      

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$P=49\pi {\text{cm}}^2$  

$\pi r^2=49\pi {\text{cm}}^2\mid :\pi$  

$r^2=49{\text{cm}}^2\mid \sqrt{}$   

$r=7\text{cm}$  

$d=2\cdot 7\text{cm}=14\text{cm}$  

$O=2\pi r=2r\cdot \pi =14\text{cm}\cdot \pi =14\pi \text{cm}\approx 14\cdot 3,14\text{cm}=43,96\text{cm}$  

$P=49\pi {\text{cm}}^2\approx 49\cdot 3,14{\text{cm}}^2=153,86{\text{cm}}^2$     

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Promień koła	Średnica koła	Obwód koła		Pole koła
		wartość dokładna	wartość przybliżona	wartość dokładna	wartość przybliżona
12 cm	24 cm	24π cm	75,36 cm	144π cm²	452,16 cm²
40 cm	80 cm	80π cm	251,2 cm	1600π cm²	5024 cm²
24 cm	48 cm	48π cm	150,72 cm	576π cm²	1808,64 cm²
7 cm	14 cm	14π cm	43,96 cm	49π cm²	153,86 cm²