∠EDC+∠C=90 degrees, ∠FBC+∠C=90 degrees.
∴∠EDC=∠FBC
∠∠DEC =∠DEB = 90,BE=DE
∴⊿BHE≌⊿DCE
∴BH=DC
Limited company
In parallelogram, ABCD ∠A=∠C, AD ∠ BC.
∴∠G=∠GBC
∠∠c =∠bhe (obtained by ⊿BHE≌⊿DCE)
∴∠A=∠BHE
∴⊿ABG∽⊿HEB(∠G=∠GBC,∠A=∠BHE)
∴AB:AG=HE:BH
∴AB*BH=AG*AE
AB = BH
∴AB square =GA*HE