[size=200]Sejam [math]\Huge a, \textcolor{blue}{b}[/math] e [math]\Huge \textcolor{red}{c}[/math] três retas dadas no plano, com [math]\Huge a\parallel \textcolor{blue}{b}[/math] e [math]\Huge \textcolor{red}{c}[/math] concorrente [math]\Huge a [/math] e [math]\Huge \textcolor{blue}{b}[/math]. Construa os círculos tangentes a [math]\Huge a, \textcolor{blue}{b}[/math] e [math]\Huge \textcolor{red}{c}[/math] . [/size]