Which of the following indicated figures are examples of adjacent angles?
1.

2.

3.

4.

Hint: We will understand the definition of adjacent angles. Then we will observe for each figure whether it indicates adjacent angles or not. And hence, we will know the answer.

Complete step-by-step answer:
Two angles having the same vertex and a common side between them are called adjacent angles.
Let us understand each figure.
In figure (1), \[\angle RQS\] and \[\angle PQS\] are two angles with the same vertex Q and a common side QS. Hence, it is an example of adjacent angles.
In figure (2), the two given angles are with the same vertex Q but they have no common side. Hence, it is not an example of adjacent angles.
In figure (3), the two given angles do not have the same vertex. Hence, it is not an example of adjacent angles.
In figure (4), \[\angle RQS\] and \[\angle PQR\] are two angles with the same vertex Q and having a common side QR. Hence, it is an example of adjacent angles.
Therefore figure (1) and figure (4) indicate adjacent angles.

Note: Two angles are said to be adjacent if they have a common vertex and a common arm.
A vertex is a point where two or more edges, lines or curves meet.