Rechenaufgaben zu Umfang und Fläche eines Kreises

\displaystyle \color{red}A

=

\displaystyle \color{lime}\pi \color{black}\cdot \color{blue}r\color{black}^2

\displaystyle \color{red}A

=

\displaystyle \color{lime}\pi \color{black}\cdot (\color{blue}5cm\color{black})^2

\displaystyle \color{red}A

=

\displaystyle \color{lime}\pi\color{black}\cdot\color{blue}5cm\color{black}\cdot\color{blue}5cm

\displaystyle \color{red}A

=

\displaystyle 78{,}54cm^2

$\displaystyle \color{red}A$	$=$	$\displaystyle \color{lime}\pi \color{black}\cdot \color{blue}r\color{black}^2$
$\displaystyle \color{red}A$	$=$	$\displaystyle \color{lime}\pi \color{black}\cdot (\color{blue}5cm\color{black})^2$
$\displaystyle \color{red}A$	$=$	$\displaystyle \color{lime}\pi\color{black}\cdot\color{blue}5cm\color{black}\cdot\color{blue}5cm$
$\displaystyle \color{red}A$	$=$	$\displaystyle 78{,}54cm^2$