Question

How is the distance to the moon is measured using mirrors placed on it?

Answer 1

By using Similarity (Maths).

Answer 2

Astronauts had placed 100 mirrors on the surface of the moon in 1969. And that’s why now you can measure the distance of moon from earth using a simple light experiment.

If you throw high power laser beams from earth towards moon, you will have to calculate how much time it takes for the beams to get reflected by the mirrors on moon and come back to earth.

And this will help you calculate the distance.