BO = DO，AB=AD，？

∴AO⊥BD

BO = DO，BC=CD，？

∴CO⊥BD

In △AOC, it is known that AO= 1 and CO=√3.

And AC=2,

∴AO？ +CO？ =AC2，？

∴∠ AOC = 90, that is, AO⊥OC.

∫BD∩OC = O

∴AB⊥ aircraft BCD.

(2) Take the midpoint M of AC to connect OM, ME and OE, and let E be the midpoint of BC to know ME∨AB, OE∨DC.

The acute angle formed by OE and EM is the angle formed by AB and CD.

Please accept it if you are satisfied, thank you!