Question
Find the area $ A $ of a circle if circumference $C = 2\pi\, \text{cm}$.
Answer
$\pi\, \text{cm}^2$
Explanation
STEP 1: find radius $ r $
To find radius $ r $ use formula:
$$ C = 2 \cdot r \cdot \pi $$After substituting $C = 2\pi\, \text{cm}$ we have:
$$ 2\pi\, \text{cm} = 2 \cdot r \cdot \pi $$ $$ r = \dfrac{ 2\pi\, \text{cm} }{ 2 \pi } $$ $$ r = 1\, \text{cm} $$STEP 2: find area $ A $
To find area $ A $ use formula:
$$ A = r^2 \cdot \pi $$After substituting $r = 1\, \text{cm}$ we have:
$$ A = \left( 1\, \text{cm} \right)^{2} \cdot \pi $$ $$ A = 1\, \text{cm}^2 \cdot \pi $$This page was created using
Circle Calculator