Find the area $ A $ of an equilateral triangle if side $a = \frac{ 3 \sqrt{ 7}}{ 7 }$.
Answer
$A = \frac{ 9 \sqrt{ 3}}{ 28 }$
Explanation
To find area $ A $ use formula:
$$ A = \dfrac{ \sqrt{ 3 } \cdot a^2 }{ 4 } $$After substituting $ a = \frac{ 3 \sqrt{ 7}}{ 7 } $ we have:
$$ A = \dfrac{ \sqrt{ 3 } \cdot \left( \frac{ 3 \sqrt{ 7}}{ 7 } \right)^2 }{ 4 } $$ $$ A = \dfrac{ \sqrt{ 3 } \cdot \frac{ 9 }{ 7 } }{ 4 }$$ $$ A = \dfrac{ \frac{ 9 \sqrt{ 3}}{ 7 } }{ 4 }$$ $$ A = \frac{ 9 \sqrt{ 3}}{ 28 } $$This page was created using
Equilateral Triangle Calculator