Adjacent Supplementary Angles
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.
Adjacent Supplementary Angles
two angles that have a common side and whose other sides lie on the same line.

Figure 1
Angles 1 and 2 in Figure 1 are adjacent supplementary angles.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.