1. The problem asks whether adjacent angles can be supplementary. 2. Adjacent angles are two angles that share a common side and a common vertex. 3. Supplementary angles are two angles whose measures add up to 180 degrees. 4. Adjacent angles can be supplementary if their non-common sides form a straight line. 5. This means the sum of the two adjacent angles is 180 degrees. 6. Therefore, the statement "Adjacent angles can be supplementary" is True.