Determine the value of the angle ADC.
Angle ADC = BDA + BDC = 54 + 33 = 87.
Since, by condition, AB = CD, the trapezoid ABCD is isosceles, then the angle BAD = ACD = 87.
In triangle ABD we define the value of angle ABD. The sum of the inner angles of the triangle is 180, then the angle ABC = (180 – BAD – BDA) = (180 – 87 – 54) = 39.
Answer: The angle ABD is 39.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.