posted by S Rey .
The distance d in kilometres to the horizon can be estimated using the formula d = root13h,where h is the height above ground level, in metres, of the observer.
Use the formula to find the distance to the horizon for an observer on the London Eye, 135m above ground.
Rearrange the formula to make h the subject.
Now wait a minute, try this yourself first. I already know how to do it and have already done two of these for you.