The reason for this is the following:
Because ∠AED = 60, EF shares ∠AED equally.
∴ ∠ 1=30
Because < 2 = 30
So < 1 = < 2.
Then EF∨BD
If you are satisfied with my answer, please adopt it as a satisfactory answer. If you have any questions, you can keep asking until you understand!