Final answer:
To determine the size of angle EDF, additional information about the geometric relationships or measurements in the diagram is needed. The process depends on various mathematical principles such as geometry or trigonometry, applied by recognizing the relevant properties or theorems.
Step-by-step explanation:
To work out the size of angle EDF, specific information about the diagram mentioned is required, which is not provided. In general, if we have a diagram with an angle labeled as angle EDF, we look for geometrical relationships or theorems that could help, such as adjacent angles, vertical angles, complementary and supplementary angles, or the various triangle angle sum properties, to name a few examples.
If angle EDF is part of a triangle, we could use the triangle angle sum property. For instance, if we know the other two angles in the triangle, we can find angle EDF by subtracting the sum of the other two angles from 180 degrees.
If the angle is part of a circle, we might apply properties from circle theorems such as angles in the same segment being equal, angles at the center being twice the angle at the circumference, or the alternate segment theorem. We might also use given information and trigonometry if it's relevant.
Without additional details or the specific values associated with angle EDF, no definitive size can be calculated for angle EDF.