The perimeter is the sum of the side lengths of a shape. A diagonal is a line segment joining two vertices of a polygon or polyhedron when those vertices are not on the same edge. We calculate as follows:
Perimeter = 4a
560 = 4a
a = 140 meters
A=(1/2)d√(4a^2 - d^2)
A = 10240.56 m^2
