STEP 1: find radius $ r $
To find radius $ r $ use formula:
$$ d = 2 \cdot r $$After substituting $ d = 24 $ we have:
$$ 24 = 2 \cdot r $$ $$ r = \dfrac{ 24 }{ 2 } $$ $$ r = 12 $$STEP 2: find circumference $ C $
To find circumference $ C $ use formula:
$$ C = 2 \cdot r \cdot \pi $$After substituting $ r = 12 $ we have:
$$ C = 2 \cdot 12 \cdot \pi $$ $$ C = 24\pi $$