Angle DCE is a central angle so it's equal to the arc facing it, which is DE, which is given as 116. So angle DCE= 116°
Angle EDF is an angle between a tangent line, DF, and a secant line, DE. So its measure is equal to half of the arc it surrounds, which is arc DE. 116/2= 58°. Angle EDF=58°.
