STEP 1: find base area $ B $
To find base area $ B $ use formula:
$$ B = a^2 $$After substituting $ a = 6 $ we have:
$$ B = 6^2 $$ $$ B = 36 $$STEP 2: find slant height $ s $
To find slant height $ s $ use Pythagorean Theorem:
$$ h^2 + \frac{ a^2 }{ 4 } = s^2 $$After substituting $ h = 4 $ and $ a = 6 $ we have:
$$ 4^2 + \frac{ 6^2 }{ 4 }= s^2 $$ $$ 16 + \frac{ 36 }{ 4 }= s^2 $$ $$ 16 + 9 = s^2 $$ $$ s^2 = 25 $$ $$ s = \sqrt{ 25 } $$$$ s = 5 $$STEP 3: find lateral surface $ L $
To find lateral surface $ L $ use formula:
$$ L = 2 \cdot a \cdot s $$After substituting $ a = 6 $ and $ s = 5 $ we have:
$$ L = 12 \cdot 5 $$$$ L = 60 $$STEP 4: find total surface $ A $
To find total surface $ A $ use formula:
$$ A = B + L $$After substituting $ B = 36 $ and $ L = 60 $ we have:
$$ A = 36 + 60 $$ $$ A = 36 + 60 $$ $$ A = 96 $$