Find the perimeter $ P $ of a rectangle if side $a = \frac{ 16 }{ 5 }$ and area $A = 18$.
Answer
$P = \frac{ 353 }{ 20 }$
Explanation
STEP 1: find side $ b $
To find side $ b $ use formula:
$$ A = a \cdot b $$After substituting $ A = 18 $ and $ a = \frac{ 16 }{ 5 } $ we have:
$$ 18 = \frac{ 16 }{ 5 } \cdot b $$$$ b = \dfrac{ 18 }{ \frac{ 16 }{ 5 } } $$$$ b = \frac{ 45 }{ 8 } $$STEP 2: find perimeter $ P $
To find perimeter $ P $ use formula:
$$ P = 2 a + 2 b $$After substituting $ a = \frac{ 16 }{ 5 } $ and $ b = \frac{ 45 }{ 8 } $ we have:
$$ P = 2 \cdot \frac{ 16 }{ 5 } + 2 \cdot \frac{ 45 }{ 8 } $$ $$ P = \frac{ 32 }{ 5 } + \frac{ 45 }{ 4 } $$ $$ P = \frac{ 353 }{ 20 } $$This page was created using
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