Question 1135801
{{{(r+r+10)*6=540}}}

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{{{cross(2r=540/6)}}}
{{{cross(r=540/12)}}}
{{{cross(r=45)}}}

{{{2r+10=540/6}}}

{{{2r+10=90}}}

{{{2r=80}}}

{{{r=40}}}

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