Question 938205
The altitude and half of one side make up a right triangle that has a hypotenuse equal to the length of a side.
Use the Pythagorean theorem,
{{{(S/2)^2+(8sqrt(3))^2=S^2}}}
{{{S^2/4+192=S^2}}}
{{{(3/4)S^2=192}}
{{{S^2=256}}}
{{{S=16}}}