STEP 1: find radius $ r $
To find radius $ r $ use formula:
$$ C = 2 \cdot r \cdot \pi $$After substituting $ C = \frac{ 38 }{ 5 } $ we have:
$$ \frac{ 38 }{ 5 } = 2 \cdot r \cdot \pi $$ $$ r = \dfrac{ \frac{ 38 }{ 5 } }{ 2 \pi } $$ $$ r \approx 1.2096 $$STEP 2: find diameter $ d $
To find diameter $ d $ use formula:
$$ d = 2 \cdot r $$After substituting $ r = 1.2096 $ we have:
$$ d = 2 \cdot 1.2096 $$ $$ d \approx 2.4192 $$