Find the side $ a $ of an equilateral triangle if altitude $h = \frac{ 21 }{ 5 }$.
Answer
$a = \frac{ 14 \sqrt{ 3}}{ 5 }$
Explanation
To find side $ a $ use formula:
$$ h = \dfrac{ \sqrt{ 3 } \cdot a }{ 2 } $$After substituting $ h = \frac{ 21 }{ 5 } $ we have:
$$ \frac{ 21 }{ 5 } = \dfrac{ \sqrt{ 3 } \cdot a }{ 2 } $$ $$ \sqrt{ 3 } \cdot a = \frac{ 21 }{ 5 } \cdot 2 $$ $$ \sqrt{ 3 } \cdot a = \frac{ 42 }{ 5 } $$ $$ a = \dfrac{ \frac{ 42 }{ 5 } }{ \sqrt{ 3 } } $$ $$ a = \frac{ 14 \sqrt{ 3}}{ 5 } $$This page was created using
Equilateral Triangle Calculator