All it is is a device that measures the angle between two objects ... The arm can be moved to a position where the sun's reflection off the mirror also reflects off mirror A and through the ...

Under this physical law, light strikes and bounces off a smooth, reflective surface with an equal angle. This is why your reflection in a bathroom mirror looks realistic, whereas your image in a ...

You (the object) and your image appear to be the same distance and angle from the mirror. The mirror acts as a line of reflection, through which your image is copied.