STEP 1: find base area $ B $
To find base area $ B $ use formula:
$$ B = a^2 $$After substituting $ a = 3.46 $ we have:
$$ B = 3.46^2 $$ $$ B = 11.9716 $$STEP 2: find lateral surface $ L $
To find lateral surface $ L $ use formula:
$$ L = 2 \cdot a \cdot s $$After substituting $ a = 3.46 $ and $ s = 4 $ we have:
$$ L = 6.92 \cdot 4 $$$$ L = 27.68 $$STEP 3: find total surface $ A $
To find total surface $ A $ use formula:
$$ A = B + L $$After substituting $ B = 11.9716 $ and $ L = 27.68 $ we have:
$$ A = 11.9716 + 27.68 $$ $$ A = 11.9716 + 27.68 $$ $$ A = 39.6516 $$