Find the area $ A $ of a pyramid if slant height $s = 5$ and base radius $r = 3$.

$A = 96$

STEP 1: find side $ a $

To find side $ a $ use formula:

$$ r = \dfrac{ a }{ 2 } $$

After substituting $ r = 3 $ we have:

$$ 3 = \dfrac{ a }{ 2 } $$ $$ a = 3 \cdot 2 $$ $$ a = 6 $$

STEP 2: 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 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:

$$ A = 36 + 60 $$ $$ A = 36 + 60 $$ $$ A = 96 $$

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