Question
Find the lateral area $ L $ of a pyramid if slant height $s = 5\, \text{cm}$ and base radius $r = 3\, \text{cm}$.
Answer
$60\, \text{cm}^2$
Explanation
STEP 1: find side $ a $
To find side $ a $ use formula:
$$ r = \dfrac{ a }{ 2 } $$After substituting $r = 3\, \text{cm}$ we have:
$$ 3\, \text{cm} = \dfrac{ a }{ 2 } $$ $$ a = 3\, \text{cm} \cdot 2 $$ $$ a = 6\, \text{cm} $$STEP 2: find lateral surface $ L $
To find lateral surface $ L $ use formula:
$$ L = 2 \cdot a \cdot s $$After substituting $a = 6\, \text{cm}$ and $s = 5\, \text{cm}$ we have:
$$ L = 12\, \text{cm} \cdot 5\, \text{cm} $$$$ L = 60\, \text{cm}^2 $$This page was created using
Pyramid Calculator