A Boy Scout technique from 55 years ago comes to mind.

It requires one arm, one thumb, and two eyes.

It needs a little geometry associated with similar triangles.

Extend your arm with one eye closed and your thumb at one extreme of
what you want to estimate. Open that eye and close the other. Estimate
the difference in distance between the two observations. Multiply that
distance by 10. Not bad for a first 'gesstimate'.

BTW, do the Boy Scout still teach this?

/s/ DD

lorentsonci wrote:

I think somone , smarter than me , will have a answer,,,, "you are
driving down the hiway and see a cell/antenna tower, it is off the
hiway but you don't know how far,,,, and you would like to know how
tall the tower is,,,????? Is there a simple (kiss) way to find out?
thanks in advance. cl.