$\displaystyle \frac{25}{\pi}\ \text{cm}$\displaystyle \frac{25}{\pi}\ \text{cm}

$\displaystyle 10\ \text{cm}$\displaystyle 10\ \text{cm}

$\displaystyle \frac{10}{\pi}\ \text{cm}$\displaystyle \frac{10}{\pi}\ \text{cm}

$\displaystyle 5\ \text{cm}$\displaystyle 5\ \text{cm}