for plane mirrors, the image is ...

the same size as the object

the same distance as the object from the mirror 

virtual = not real, fake

upright

laterally inverted 

3.15

Light travels in straight lines, therefore it directly reaches your eye

We see some objects, because they are reflected by the light and they are light sources.

Also, we see them because the sun strikes the object and some of the light is reflected into our eyes

Opaque materials do not let light through but transparent materials do let light through.

the picture shows that: 

Angle of incidence = Angle of reflection