Lamp posts are to be installed on the equator of a perfectly spherical planet in such a way that they illuminate the entire equator. A few very tall lamps could be used - three is the minimum - or many short lamps. In what way should this be done so that the total height of the posts is as small as possible?

http://cs.marlboro.edu/ courses/ spring2010/dedhour/ problems/ equator_illumination/ problem
last modified Wednesday February 10 2010 11:52 am EST