STEP 1: find base area $ B $
To find base area $ B $ use formula:
$$ B = a^2 $$After substituting $a = 8\, \text{cm}$ we have:
$$ B = \left( 8\, \text{cm} \right)^{2} $$ $$ B = 64\, \text{cm}^2 $$STEP 2: find lateral surface $ L $
To find lateral surface $ L $ use formula:
$$ A = B + L $$After substituting $A = 304\, \text{cm}$ and $B = 64\, \text{cm}^2$ we have:
$$ 304\, \text{cm} = 64\, \text{cm}^2 + L $$ $$ L = 304\, \text{cm} - 64\, \text{cm}^2 $$ $$ L = 240\, \text{cm} $$STEP 3: find slant height $ s $
To find slant height $ s $ use formula:
$$ L = 2 \cdot a \cdot s $$After substituting $L = 240\, \text{cm}$ and $a = 8\, \text{cm}$ we have:
$$ 240\, \text{cm} = 2 \cdot 8\, \text{cm} \cdot s $$$$ 240\, \text{cm} = 16\, \text{cm} \cdot s $$$$ s = \dfrac{ 240\, \text{cm} }{ 16\, \text{cm} } $$$$ s = 15 $$