Find the radius $ r $ of a cone if height $h = 34.5$ and slant height $l = 40$.
Answer
$r = 20.2423$
Explanation
To find side $ r $ use Pythagorean Theorem:
$$ r^2 + h^2 = l^2 $$After substituting $ h = 34.5 $ and $ l = 40 $ we have:
$$ r ^ {\,2} + 34.5^2 = 40^2 $$ $$ r ^ {\,2} = 40^2 - 34.5^2 $$ $$ r ^ {\,2} = 1600 - 1190.25 $$ $$ r ^ {\,2} = 409.75 $$ $$ r = \sqrt{ 409.75 } $$$$ r = 20.2423 $$This page was created using
Cone Calculator