Let E(e, 0)

Quadrilateral DCOE is a parallelogram with area = OE * ordinate d = 4e = 4 and e = 1.

OE = CD = 1, abscissa of d = abscissa of c+CD = 3+1= 4; The ordinate of d is the same as that of c, which is 4, d (4,4).

Substitute y = k/x and k = 16.

(2)

△CFP is similar to △COA, △CDP is similar to △CBA, and FP/OA = CP/CA = PD/AB.

PDCF is a diamond, FP=PD, then OA = AB, that is, OABC is also a diamond, OA=OC=AB=5.

A (5 5,0), the abscissa of B = C+OA = 3+5 = 8, the ordinate of B and C is the same, and B (8,4).