Question

Lungimea unui cerc cu diametrul de 12 cm este egala cu... cm​

Answer 1

2 pi r = 2 × 6 x pi = 12 pi
Răspuns: 12 pi
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Answer 2

 

$\displaystyle\\\text{Se da:}\\ D = 12~cm~~\text{(Diametrul cercului)}\\\\\text{Se cere:}\\\\ L = ?~cm~~\text{(Lungimea cercului)}\\\\\text{Formule folosite:}\\\\\text{Formula 1: }\\\\L = \pi D=\pi \times 12=\boxed{12\pi~cm} \\\\\text{Formula 2: }\\\\L=2\pi R~~~~\text{unde R este raza cercului.}\\\\R=\frac{D}{2}=\frac{12}{2}=6~cm\\\\L=2\pi R=2\pi \times6=\boxed{12\pi~cm}$