Question 1073214
Two choices.  Which ends have the triangles?  Along the 45 foot sides, or along the 100 foot sides?


If the 100 foot sides are capped with the triangles, then each triangle leg y gives you  {{{y^2+y^2=100^2}}};
{{{2y^2=100*100}}}
{{{y^2=50*100}}}
{{{y=sqrt(50*100)}}}
{{{y=10*sqrt(2*5*5)}}}
{{{y=50*sqrt(2)}}}
-
total area would be  {{{45*100+(50*sqrt(2))^2}}}
{{{4500+5000}}}
9500