∴ quadrilateral ACFE is a diamond.

∴∠FBA=∠BAO=45

∴∠FBO=90

So AOBG is square.

∴AO=AG= 1/2AC= 1/2AE

△AEG is a right triangle of 30.

∴∠CFB=∠E=30 =∠ACF

∠ACB=45

∴∠bcf=45-30 = 15 = 1/2∠CFB = 1/2∠e

Certificate of completion