STEP 1: find base area $ B $
To find base area $ B $ use formula:
$$ B = a^2 $$After substituting $ a = 75 $ we have:
$$ B = 75^2 $$ $$ B = 5625 $$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 = 48 $ and $ a = 75 $ we have:
$$ 48^2 + \frac{ 75^2 }{ 4 }= s^2 $$ $$ 2304 + \frac{ 5625 }{ 4 }= s^2 $$ $$ 2304 + \frac{ 5625 }{ 4 } = s^2 $$ $$ s^2 = \frac{ 14841 }{ 4 } $$ $$ s = \sqrt{ \frac{ 14841 }{ 4 } } $$$$ s = \frac{ 3 \sqrt{ 1649}}{ 2 } $$STEP 3: find lateral surface $ L $
To find lateral surface $ L $ use formula:
$$ L = 2 \cdot a \cdot s $$After substituting $ a = 75 $ and $ s = \frac{ 3 \sqrt{ 1649}}{ 2 } $ we have:
$$ L = 150 \cdot \frac{ 3 \sqrt{ 1649}}{ 2 } $$$$ L = 225 \sqrt{ 1649 } $$STEP 4: find total surface $ A $
To find total surface $ A $ use formula:
$$ A = B + L $$After substituting $ B = 5625 $ and $ L = 225 \sqrt{ 1649 } $ we have:
$$ A = 5625 + 225 \sqrt{ 1649 } $$ $$ A = 5625 + 225 \sqrt{ 1649 } $$ $$ A = 14761.7732 $$