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!