Question
Find the area $ A $ of an equilateral triangle if side $a = 15\, \text{cm}$.
Answer
$\dfrac{ 225 \sqrt{ 3}}{ 4 }\, \text{cm}^2$
Explanation
To find area $ A $ use formula:
$$ A = \dfrac{ \sqrt{ 3 } \cdot a^2 }{ 4 } $$After substituting $a = 15\, \text{cm}$ we have:
$$ A = \dfrac{ \sqrt{ 3 } \cdot \left( 15\, \text{cm} \right)^{2} }{ 4 } $$ $$ A = \dfrac{ \sqrt{ 3 } \cdot 225\, \text{cm}^2 }{ 4 }$$ $$ A = \dfrac{ 225 \sqrt{ 3 }\, \text{cm}^2 }{ 4 }$$ $$ A = \frac{ 225 \sqrt{ 3}}{ 4 }\, \text{cm}^2 $$This page was created using
Equilateral Triangle Calculator