Question

two angles are supplementary if and only if the sum of their measures is 180. supplementary angles are: - which means they form a in this figure, <abd and <dbc form a linear pair, and thus <abd and <dbc must be supplementary. that is, m<abd + m<dbc = 180.

Explanation:

Step1: Recall supplementary - angle concept

Supplementary angles sum to 180 degrees and can be adjacent or non - adjacent. When adjacent, they form a straight line.

Step2: Fill in the blanks

The first blank for the property of supplementary angles when adjacent is "adjacent angles", and they form a "straight line".

Answer:

adjacent angles; straight line