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Passing through point A, point E is AC⊥BD and EF⊥BD, and the two triangles are △ABC and △EFD respectively, and AC=EF.

Because ∠B is equal to 60, the right angle at ∠ BAC is equal to 30, and the angle of 30 is equal to half of the hypotenuse, that is, BC= 1/2AB= 1.

Then AC= root number 3 is obtained according to Pythagorean theorem.

As shown in figure AC=EF, so EF= root number 3.

Because ∠ EDF = 30, ED = 2ef (the right angle side of 30 is equal to half of the hypotenuse).

So the root number 3 of ED=2