Find the perimeter $ P $ of a rectangle if side $a = 7$ and area $A = 42$.
Answer
$P = 26$
Explanation
STEP 1: find side $ b $
To find side $ b $ use formula:
$$ A = a \cdot b $$After substituting $ A = 42 $ and $ a = 7 $ we have:
$$ 42 = 7 \cdot b $$$$ b = \dfrac{ 42 }{ 7 } $$$$ b = 6 $$STEP 2: find perimeter $ P $
To find perimeter $ P $ use formula:
$$ P = 2 a + 2 b $$After substituting $ a = 7 $ and $ b = 6 $ we have:
$$ P = 2 \cdot 7 + 2 \cdot 6 $$ $$ P = 14 + 12 $$ $$ P = 26 $$This page was created using
Rectangle Calculator