In geometry, the types of angles are classified according to the measure. Further we have pairs of angles such as, complementary angles, supplementary angles, adjacent angles and linear pair. Learning these basics thoroughly will help us to learn more concepts on geometry. In the real life examples, we come across adjacent angles frequently like, the angles made by any three fingers, angle made by a door with the wall, the angles made by the vein of a leaf with the midrib etc. In this section let us study about the definition, real life examples and the problems based on the definition of adjacent angles.

Pair of angles which have a common arm and a common vertex, whose interiors do not overlap.

In the above figure, B is the common vertex and BD is the common arm.

The pair of adjacent angles are $\angle ABC$ and $\angle CBD$.