Question 1037402
Choose any side to serve as a base.  A good choice is the 90 meter side, because this triangle is isosceles with two equal sides  225 meters.  The triangle is composed of two congruent right triangles sharing a height; this height being the longer leg of either right triangle.  Call this h.


{{{45^2+h^2=225^2}}}
{{{h^2=225^2-45^2}}}
{{{h^2=(225+45)(225-45)}}}
{{{h^2=270*180}}}
{{{h^2=3*3*3*2*5*2*3*3*2*5}}}
{{{h^2=2^3*3^5*5^2}}}
{{{h=2*3*5*sqrt(2*3)}}}
OR
{{{highlight_green(h=30*sqrt(6))}}}



Formula for area of a triangle:  {{{highlight_green((1/2)bh)}}}, using b for base, and the same h for height.