STEP 1: find base diagonal $ d $
To find base diagonal $ d $ use Pythagorean Theorem:
$$ h^2 + \frac{ d^2 }{ 4 } = e^2 $$After substituting $h = 24\, \text{cm}$ and $e = 26\, \text{cm}$ we have:
$$ \left( 24\, \text{cm} \right)^{2} + \frac{ d^2 }{ 4 } = \left( 26\, \text{cm} \right)^{2} $$ $$ \frac{ d^2 }{ 4 } = \left( 26\, \text{cm} \right)^{2} - \left( 24\, \text{cm} \right)^{2} $$ $$ \frac{ d^2 }{ 4 } = 676\, \text{cm}^2 - 576\, \text{cm}^2 $$ $$ d^2 = 100\, \text{cm}^2 \cdot 4 $$ $$ d^2 = 400\, \text{cm}^2 $$ $$ d = \sqrt{ 400\, \text{cm}^2 } $$$$ d = 20\, \text{cm} $$STEP 2: find side $ a $
To find side $ a $ use formula:
$$ d = \sqrt{ 2 } \cdot a $$After substituting $d = 20\, \text{cm}$ we have:
$$ 20\, \text{cm} = \sqrt{ 2 } \cdot a $$ $$ a = \dfrac{ 20\, \text{cm} }{ \sqrt{ 2 } } $$ $$ a = 10 \sqrt{ 2 }\, \text{cm} $$