Vă rog dau coroana am nevoie urgent ex 3

[tex]\it \Delta ODE-isoscel,\ OD=OE\ (raze) \Rightarrow \widehar{ODE}=\widehat{OED}=72^o\\ \\ \widehat{EOD}=180^o-2\cdot72^o=36^o \Rightarrow m(\stackrel\frown{DE})=36^o\\ \\ \widehat{DFE}=\dfrac{m(\stackrel\frown{DE})}{2}=\dfrac{36^o}{2}=18^o[/tex]