The opposite angles of a parallelogram are congruent. This means that
angle D = angle B
angle A = angle C
If angle D is 124 degrees, then
angle B = 124 degrees
Recall, the sum of the angles on a straight line is 180 degrees. These angles are also called linear pairs. This means that
angle ABC and angle EBC are linear pairs
angle ABC + angle EBC = 180
124 + angle EBC = 180
angle EBC = 180 - 124 = 56 degrees
If line CE = line BE, it means that triangle EBC is an isosceles triangle because it has two congruent sides. In an isosceles triangle, the base angles are congruent. This means that
angle ECB and angle EBC are congruent
Thus,
angle ECB + angle EBC = 56 degrees
The sum of the angles in a triangle is 180 degrees. This means that
angle ECB + angle EBC + angle BEC = 180
56 + 56 + angle BEC = 180
112 + angle BEC = 180
angle BEC = 180 - 112
angle BEC = 68 degrees
Thus, the correct option is
3) 68 degrees
