Question 1078592
Not cleanly described, and there may be a typo.
Are all distances between adjacent corners 375 feet?
Distances BC and CD are listed as 375" (375 inches);
distance AB is listed as 375' (375 feet),
and distance AD is not mentioned at all.
The angles at each corner are not mentioned either.
The plot shape could be a rhombus, like this {{{drawing(300,180,0,10,0,6,triangle(1,1,6,1,9,5),
line(1,1,6,1),line(9,5,6,1),line(9,5,4,5),line(1,1,4,5),
locate(0.8,1,A),locate(6,1,B),locate(9,5.5,C),locate(3.8,5.5,D))}}} .
with all sides of equal length, but no right angles.
Or maybe there are only three sides with the same length,
but no right angle at B, like this {{{drawing(300,270,0,10,0,9,triangle(1,1,6,1,9,5),
line(1,1,6,1),line(9,5,6,1),line(9,5,5,8),line(1,1,5,8),
locate(0.8,1,A),locate(6,1,B),locate(9,5.5,C),locate(4.8,8.5,D))}}} .
In either case, not knowing the angle at B,
we cannot use triangle ABC to calculate the length of AC.
 
Does the plot look like this {{{drawing(300,300,0,10,0,10,triangle(1,1,9,1,9,9),rectangle(9,1,8.7,1.3),
rectangle(1,1,9,9),locate(0.8,1,A),locate(9,1,B),locate(9,9.5,C),locate(0.8,9.5,D))}}}? A square?
In that case, with AB=BC=CD=DA=375 feet, and a right angle at B,
ABC is a right triangle, with hypotenuse AC, of length
{{{sqrt((375ft)^2+(375ft)^2)=sqrt(2)*375ft=about530}}}{{{ft}}} .