Question
Find the radius $ r $ of a sphere if area $A = 0.9\, \text{cm}$.
Answer
$0.2676$
Explanation
To find radius $ r $ use formula:
$$ A = 4 \cdot r^2 \cdot \pi $$After substituting $A = 0.9\, \text{cm}$ we have:
$$ 0.9\, \text{cm} = 4 \cdot r^2 \cdot \pi $$ $$ r^2 \cdot \pi = \dfrac{ 0.9\, \text{cm} }{ 4 } $$ $$ r^2 \cdot \pi = 0.225\, \text{cm} $$ $$ r = \sqrt{ \frac{ 0.225\, \text{cm} }{\pi} } $$ $$ r \approx 0.2676 $$This page was created using
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