STEP 1: find base area $ B $
To find base area $ B $ use formula:
$$ B = a^2 $$After substituting $ a = 19 $ we have:
$$ B = 19^2 $$ $$ B = 361 $$STEP 2: find lateral surface $ L $
To find lateral surface $ L $ use formula:
$$ L = 2 \cdot a \cdot s $$After substituting $ a = 19 $ and $ s = 22.5 $ we have:
$$ L = 38 \cdot 22.5 $$$$ L = 855 $$STEP 3: find total surface $ A $
To find total surface $ A $ use formula:
$$ A = B + L $$After substituting $ B = 361 $ and $ L = 855 $ we have:
$$ A = 361 + 855 $$ $$ A = 361 + 855 $$ $$ A = 1216 $$