Farex is really great, because the similarity principle in geometry was applied to measure the height of pyramids more than 2000 years ago, and the geometry we are studying now-Euclid geometry was founded by the Greek scholar Euclid many years after Farex.

The height of the pyramid is H, and the height of the Pharisee is H. When the projection of the position where the Pharisee stood coincides with the projection of the pyramid, his assistant measures the distance A between the Pharisee and the projection and the distance B between the Pharisee and the pyramid. According to the principle of triangle similarity, there are

H/h=(a+b)/a, we can find that:

H=(a+b)h/a