1. i = r Wave Front REFLECTION
A wave front of a wave striking a straight barrier follows the law of reflection. This law states that: "The angle of incidence equals the angle of reflection".
The angle of incidence is the angle between the direction of the incoming wave and a normal drawn to the surface. The angle of reflection is the angle between the direction of the reflected wave and the normal to the surface.
i = r

2. Properties of Pulse Waves
Reflection
The pulse reflects upside down from a fixed end.
(Phase change)

3. The pulse reflects upside down from a fixed end.

4. A pulse reflected from a free end is upright.

5. A pulse reflected from a free end is upright.

6. The pulse reflects upside down from a fixed end.