a,\(=>\angle\left(EDF\right)=180^o-\angle\left(DEF\right)-\angle\left(DFE\right)=80^O\)
b,\(\angle\left(EDM\right)=\angle\left(MDF\right)=\dfrac{\angle\left(EDF\right)}{2}=40^o\)
c,\(\angle\left(DME\right)=\angle\left(DFE\right)+\angle\left(MDF\right)=80^o\)