Question 630246
{{{A=pi*r^2}}}


Area of three circles = {{{pi*2^2 + pi*3^2 + pi*4^2}}}

{{{A=pi*4 + pi*9 + pi*16}}}
{{{A=pi*29}}}


Area of unknown circle = {{{pi*r^2=pi*29}}}


Divide both sides by pi:


{{{r^2=29}}}


{{{r=sqrt(29) }}}


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Dr. Robert J. Rapalje, Retired
Seminole State College of Florida