Since its construction in 1821, Marblehead Lighthouse has stood at

Question

the entrance to Sandusky Bay, guiding sailors along Lake Erie’s rocky
shores. The 65-foot tower is one of Ohio’s best-known landmarks and
the oldest continuously operating lighthouse on the Great Lakes.

1. The range of a lighthouse is the maximum distance at which its
light is visible. In the figure, point A is the farthest point from
which it is possible to see the light at the top of the lighthouse L.
The distance along Earth s is the range. Assuming that the radius
of Earth is 4000 miles, find the range of Marblehead Lighthouse.