Find the area $ A $ of a circle if circumference $C = 18$.
Answer
$A = 8.207\pi$
Explanation
STEP 1: find radius $ r $
To find radius $ r $ use formula:
$$ C = 2 \cdot r \cdot \pi $$After substituting $ C = 18 $ we have:
$$ 18 = 2 \cdot r \cdot \pi $$ $$ r = \dfrac{ 18 }{ 2 \pi } $$ $$ r \approx 2.8648 $$STEP 2: find area $ A $
To find area $ A $ use formula:
$$ A = r^2 \cdot \pi $$After substituting $ r = 2.8648 $ we have:
$$ A = 2.8648^2 \cdot \pi $$ $$ A = 8.207 \cdot \pi $$This page was created using
Circle Calculator