Answer: D1 = x = 50 degrees.
Explanation:
Use:
The sum of all angles of a parallelogram = 360 degrees.
Opposite angles of a parallelogram are equal.
The sum of all angles of a triangle = 180 degrees.
If AB = BE, then A1 = E1.
All the following values are in degrees:
A1 = 28
A2 = 28
B = 124
C = 56
D1 = 50
D2 = 74
E1 = 28
E2 = 78
E3 = 74