Question 1152805


let the length of the dividing line be {{{x}}}


{{{x=sqrt((n*a^2+m*b^2)/(n+m))}}}...........given {{{a=60}}}, {{{b=90}}}, the {{{90m}}} side is equal to {{{1/3}}} of the whole area, then {{{60m}}} side is equal to {{{2/3}}}, => areas are in {{{1:2}}} ratio=>{{{n=1}}} and {{{m=2}}}

{{{x=sqrt((1*60^2+2*90^2)/(1+2))}}}

{{{x=sqrt((3600+2*8100)/3)}}}

{{{x=sqrt((3600+16200)/3)}}}

{{{x=sqrt((19800)/3)}}}

{{{x=sqrt(6600)}}}

{{{x=81.24}}}


answer:

C. {{{81.24m}}}