1. Two angles are adjacet when they are next to each other, that is, the share a side and the vertex.
2. Two angles anre supplementary when their sum equals 180º
3. Two anfgles are vertical angles when they share the vertex but no side, they are usually formed when two lines cross each other formin an X shape.
4. Linear pair angles are formed when two lines cross each other at one point and both angles are over the same line. These angles are always supplementary.
5. Complementary angles are those that add up to 90º.
For angles ∠D and ∠E, they share one side and vertex, so they are adjacent, and they add up to 90º |_, so they are complementary.