Answer:
The correct statements are:
1: mEFD = mEGD
3: mED = mFD
5: mFD = 120°
Step-by-step explanation:
Let's analyse each statement:
1: mEFD = mEGD
Let's find the value of the angle ECD, using the sum of the internal angles of a quadrilateral:


The angle ECD is a central angle, related to the arc ED, so the arc ED also has 120°.
The angle EFD inscribes the arc ED, so we have:


So the angles mEFD and mEGD are equal. The statement is TRUE.
2. mEGD = mECD
This statement is FALSE, because mEGD = 60° and mECD = 120°
3. mED = mFD
If mED is 120° and mEF = mFD, we have:



So the statement is TRUE, both arcs have 120°.
4. mEF = 60°
This statement is FALSE, because we calculated before that mEF = mFD = 120°
5. mFD = 120°
This statemente is TRUE, because we calculated before that mFD = 120°.
So the correct statements are 1, 3 and 5