23。 (1) proves that since the quadrilateral ABCD is rectangular,

So the angle ABC=90 degrees,

So the angle EBF+EBO=90 degrees, the angle BOF+ the angle BFO=90 degrees,

Because BM is perpendicular to AC, m, OF is perpendicular to OD and p,

So angle OCP+ angle EBO=90 degrees, angle BOF+ angle POC=90 degrees,

So angle EBF= angle OCP, angle BFO= angle POC,

So triangle OPC is similar to triangle feb.