Using the angle addition postulate, the measure of angle ABC is: 126°.
The angle addition postulate states that, the sum of two smaller angles that make up a larger angle will equal the measure of the larger angle.
Thus:
m∠ABD = 48
m∠DBC = 78
Therefore:
m∠ABC = m∠ABD + m∠DBC
Substitute
m∠ABC = 48 + 78
m∠ABC = 126°
Therefore, using the angle addition postulate, the measure of angle ABC is: 126°.
Learn more about angle addition postulate on:
https://brainly.com/question/24782727