dentist often uses a mirror to see the enlarged image of defective teeth, what is the nature of that mirror ? write two more uses of such mirror.

this could help my friend

The dentist uses a CONCAVE MIRROR to observe a magnified image of the tooth. As we know, a concave mirror forms a virtual, erect and magnified image...

Explanation:

i guess that visual aids present persuasive examples to what you are presenting, some factors would be theme (does it fit with the color, information, what you are presenting), size (can you see it, is it a big enough span of data/information), and overall look of the visual aid.

hope this : )

d.7.5cm is your answer