STEP 1: find side $ a $
To find side $ a $ use formula:
After substituting $B = 16\, \text{cm}$ we have:
$$ B = a^2 $$ $$ a^2 = 16\, \text{cm} $$ $$ a = \sqrt{ 16\, \text{cm} } $$ $$ a = 4 $$STEP 2: find lateral surface $ L $
To find lateral surface $ L $ use formula:
$$ L = 2 \cdot a \cdot s $$After substituting $a = 4\, \text{cm}^0$ and $s = 8\, \text{cm}$ we have:
$$ L = 8 \cdot 8\, \text{cm} $$$$ L = 64\, \text{cm} $$STEP 3: find total surface $ A $
To find total surface $ A $ use formula:
$$ A = B + L $$After substituting $B = 16\, \text{cm}$ and $L = 64\, \text{cm}$ we have:
$$ A = 16\, \text{cm} + 64\, \text{cm} $$ $$ A = 16\, \text{cm} + 64\, \text{cm} $$ $$ A = 80\, \text{cm} $$