Question
Find the circumference $ C $ of a circle if diameter $d = 7.5\, \text{mm}$.
Answer
$7.5\pi\, \text{mm}$
Explanation
STEP 1: find radius $ r $
To find radius $ r $ use formula:
$$ d = 2 \cdot r $$After substituting $d = 7.5\, \text{mm}$ we have:
$$ 7.5\, \text{mm} = 2 \cdot r $$ $$ r = \dfrac{ 7.5\, \text{mm} }{ 2 } $$ $$ r = 3.75\, \text{mm} $$STEP 2: find circumference $ C $
To find circumference $ C $ use formula:
$$ C = 2 \cdot r \cdot \pi $$After substituting $r = 3.75\, \text{mm}$ we have:
$$ C = 2 \cdot 3.75\, \text{mm} \cdot \pi $$ $$ C = 7.5\pi\, \text{mm} $$This page was created using
Circle Calculator