Question

Tem-se um circulo de raio 9cm.Determinar:
a) o perimetro desse circulo
b) a area desse circulo

Answer 1

$r=9\ cm\\ \pi =3,14\\\\\\ a)\ C=2 \pi r\to C=2*3,14*9\to C=56,52\ cm\\\\\\\\ b) A=\pi r^2\to A=3,14*9^2\to A=3,14*81\to A=254,34\ cm^2$