The lines AB and CD intersect at E. The angles BEC and AED form a vertical pair of angles and are equal in magnitude.
When AED measures 40.3 degrees, BEC also measures 40.3 degrees.
When AED measures 44.175 degrees, BEC also measures 44.175 degrees.
In geometry, when two lines intersect they form two pair of vertical angles. remember that a pair of angles is said to be vertical if the angles are formed from two intersecting lines and the angles are not adjacent. In this case angles BEC and AED are vertical angles and vertical angles are always congruent. Therefore, if AED measures 40.30, then so does BEC. Similarly, if AED measures 44.175, BEC does also.