Question

daca roata unei trasuri are diametrul de 80 cm, calculeaza lungimea circumferintei rotii

Answer 1

$L_{cerc}=2 \pi R$
$d=2R=>R= \frac{d}{2}= \frac{80}{2}=40cm$
$L_{cerc}=2 \pi R=2 \pi *40cm=80 \pi cm$