Question
Find the base area $ A_B $ of a cone if diameter $d = 18\, \text{cm}$ and height $h = 12\, \text{cm}$.
Answer
$81\pi\, \text{cm}^2$
Explanation
STEP 1: find radius $ r $
To find radius $ r $ use formula:
$$ d = 2 \cdot r $$After substituting $d = 18\, \text{cm}$ we have:
$$ 18\, \text{cm} = 2 \cdot r $$ $$ r = \dfrac{ 18\, \text{cm} }{ 2 } $$ $$ r = 9\, \text{cm} $$STEP 2: find base area $ AB $
To find base area $ AB $ use formula:
$$ AB = r^2 \cdot \pi $$After substituting $r = 9\, \text{cm}$ we have:
$$ AB = \left( 9\, \text{cm} \right)^{2} \cdot \pi $$ $$ AB = 81\, \text{cm}^2 \cdot \pi $$This page was created using
Cone Calculator