Menu Close

Question-154210




Question Number 154210 by Eric002 last updated on 15/Sep/21
Commented by Eric002 last updated on 15/Sep/21
the indentical circles of radius r, inside  a triangle, each of them tangent to tow   sides of the triangle.  prove:(1/r)=(1/R_(in) )+(1/R_(out) )  R_(in) =inradius of ΔABC  R_(out) =circumradius of ΔABC
$${the}\:{indentical}\:{circles}\:{of}\:{radius}\:{r},\:{inside} \\ $$$${a}\:{triangle},\:{each}\:{of}\:{them}\:{tangent}\:{to}\:{tow}\: \\ $$$${sides}\:{of}\:{the}\:{triangle}. \\ $$$${prove}:\frac{\mathrm{1}}{{r}}=\frac{\mathrm{1}}{{R}_{{in}} }+\frac{\mathrm{1}}{{R}_{{out}} } \\ $$$${R}_{{in}} ={inradius}\:{of}\:\Delta{ABC} \\ $$$${R}_{{out}} ={circumradius}\:{of}\:\Delta{ABC} \\ $$
Commented by mr W last updated on 18/Sep/21
see Q154415
$${see}\:{Q}\mathrm{154415} \\ $$

Leave a Reply

Your email address will not be published. Required fields are marked *