In square ABCD, point P is a point on edge CD, and PE ⊥ dB, PF ⊥ Ca, perpendicular feet are points E and f respectively, What is the quantitative relationship between PE + PF and the diagonal length of a square

In square ABCD, point P is a point on edge CD, and PE ⊥ dB, PF ⊥ Ca, perpendicular feet are points E and f respectively, What is the quantitative relationship between PE + PF and the diagonal length of a square

PE+PF=AC/BD
Using Pythagorean theorem and similar triangle, three angles are equal and three sides are proportional
Certificate: PE = PD twice of Geng Hao,
Pf = PC twice the size of the change,
PD + PC = CD, BD / AC = more than twice the size of CD,
So double PD + double PC = double CD = BD / AC
That is PE + pf = AC / BD