punkty-a-b-c-i-d-leza-na-okregu-o-2

$\alpha=36^\circ$\alpha=36^\circ , $\beta=72^\circ$\beta=72^\circ

$\alpha=54^\circ$\alpha=54^\circ , $\beta=72^\circ$\beta=72^\circ

$\alpha=36^\circ$\alpha=36^\circ , $\beta=108^\circ$\beta=108^\circ

$\alpha=72^\circ$\alpha=72^\circ , $\beta=72^\circ$\beta=72^\circ