Answer:
[tex]\huge\boxed{1.\ C\approx38cm;\ 2.\ C\approx57ft;\ 3.\ C\approx50in.}[/tex]
Step-by-step explanation:
The formula of a circumference of a circle:
[tex]C=2\pi r\\\\r-\text{radius}[/tex]
[tex]1.\\r=6cm\\\\C=2\pi\cdot6=12\pi\\\\\pi\approx3.14\\\\C\approx12\cdot3.14=37.68\approx38(cm)\\\\2.\\r=9ft\\\\C=2\pi\cdot9=18\pi\\\\\pi\approx3.14\\\\C\approx18\cdot3.14=56.52\approx57(ft)\\\\3.\\2r=16in.\to r=8in.\\\\C=2\pi\cdot8=16\pi\\\\\pi\approx3.14\\\\C\approx16\cdot3.14=50.24\approx50(in.)[/tex]
