Question 580595
With the altitude drawn, you have two 30-60-90
triangles. The altitude is opposite the
60 degree angle.
The ratio of the side of the equilateral to
the altitude is {{{ 2/sqrt(3) }}}
Call the side {{{s}}}
{{{ 2/sqrt(3) = s/20 }}}
{{{ 2*20 = s*sqrt(3) }}}
{{{ s = 40/sqrt(3) }}}
{{{ s = (40/sqrt(3))*( sqrt(3)/sqrt(3) ) }}}
{{{ s = ( 40*sqrt(3) )/3 }}}
and
{{{ s = (40*1.732)/3 }}}
{{{ s = 23.09 }}}