According to your idea, I hereby certify the following for your reference:
Pass p stands for PM⊥AD, cross AD stands for m, pa = pd, ma = MD.
Connect BM, abcd is a diamond, ∠ Bad = 60, ∴⊿ABD is an equilateral triangle, ∴BM⊥AD.
∴AD⊥ Port and Maritime Bureau
At ⊿pbc∫e and F are the midpoint of PC and BC respectively, ∴∫e, F//Pb.
⊿CBD is an equilateral triangle, ∴DF⊥BC,∴DF//BM.
∴ surface PMB// surface DEF== >AD⊥ surface definition