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Circonferenza:
$\small c= 196\pi : \dfrac{4}{3}$
$\small c= \cancel{196}^{49}\pi·\dfrac{3}{\cancel4_1}$
$\small c= 49\pi·3 = 147\pi\,cm;$
raggio:
$\small r= \dfrac{c}{2\pi}$
$\small r= \dfrac{147\cancel{\pi}}{2\cancel{\pi}}$
$\small r= 73,5\,cm;$
area:
$\small A= r^2·\pi$
$\small A= 73,5^2·\pi = 5402,25\pi\,cm^2.$