FG parallel AD, ∠GFP=∠HDP, △ GFP △ HDP, HP=PG, GF=HD.
The quadrilateral ABCD is a diamond, CD=CB, ∠HDC=∠ABC=60, ∠ABC=∠BEF=60,
∠GBc=60,∠HDC=∠GBC,△HDCP?△GBC
CH=CG,∠DCH=∠BCG
∠DCH+∠HCB=∠BCG+∠HCB= 120
∠hcg= 120,ch=cg,ph=pg,pg⊥pc,pg/pc=√3