Per the post below, here's a case where the entry in Wikipedia has an incorrect formula, an opportunity for someone to put it right. I haven't done so at this point, but maybe as a school project...?
Note the provided formula for Height (H), can't be right because linear dimensions scale proportionately, linearly, i.e. if you double edges 'a', you thereby double height 'h'. What's provided is a non-linear function though.
--- In firstname.lastname@example.org, "coyote_starship" <kirby.urner@...> wrote:
--- In email@example.com, "coyote_starship" <kirby.urner@> wrote: > > --- In firstname.lastname@example.org, Adrian Rossiter <adrian_r@> wrote: > > ... > > > For the unit edge icosahedron the pyramid height is therefore > > > > 1/sqrt(phi+2) = approx .5257 > > > > DAve also got back to me with this same answer, expressed as > (1/sin(72))/2. >
Going by this site, and setting a = e, solving for h: