STEP 1: find radius $ r $
To find radius $ r $ use formula:
$$ d = 2 \cdot r $$After substituting $ d = 100 $ we have:
$$ 100 = 2 \cdot r $$ $$ r = \dfrac{ 100 }{ 2 } $$ $$ r = 50 $$STEP 2: find volume $ V $
To find volume $ V $ use formula:
$$ V = \dfrac{ 4 \cdot r^2 \cdot \pi}{ 3 } $$After substituting $ r = 50 $ we have:
$$ V = \dfrac{ 4 \cdot 50^2 \cdot \pi}{ 3 } $$ $$ V = \dfrac{ 4 \cdot 2500 \cdot \pi}{ 3 }$$ $$ V = \dfrac{ 10000 \cdot \pi}{ 3 }$$ $$ V = \frac{ 10000 }{ 3 } \cdot \pi $$