Question 825069
two sides are equal, so isosceles.
Cut this into two equal right triangles from the point opposite the 8 m length to the middle of this 8 m length.  The segment joining these is the height, and is a leg of each of the right triangles.  


h is for height, NOT hypotenuse here.
{{{h^2+(8/2)^2=5^2}}}
{{{h^2=25-16=9}}}
{{{h=3}}}