Question

me ajudem nessa pfv..

Answer 1

$C=2. \pi .r \\ \\ Se~~d=2r \\ \\ 20=2r \\ r=20\div2 \\ r=10cm \\ \\ Logo \\ \\ C=2.3.10 \\ C=60cm \\ \\ ------------ \\ \\ area= \pi r^2 \\ \\ A=3.10^2 \\ \\ area=3.100 \\ A=300cm^2$