Find the area $ A $ of a circle if diameter $d = 15$.
Answer
$A = \frac{ 225 }{ 4 }\pi$
Explanation
STEP 1: find radius $ r $
To find radius $ r $ use formula:
$$ d = 2 \cdot r $$After substituting $ d = 15 $ we have:
$$ 15 = 2 \cdot r $$ $$ r = \dfrac{ 15 }{ 2 } $$ $$ r = \frac{ 15 }{ 2 } $$STEP 2: find area $ A $
To find area $ A $ use formula:
$$ A = r^2 \cdot \pi $$After substituting $ r = \frac{ 15 }{ 2 } $ we have:
$$ A = \left(\frac{ 15 }{ 2 }\right)^2 \cdot \pi $$ $$ A = \frac{ 225 }{ 4 } \cdot \pi $$This page was created using
Circle Calculator