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20 16 Chongming Ermo Mathematics Grade 3
Answer: (full score of this question 12) There are two small questions in this question, 1 full score of the small question (6 points) and the full score of the second small question (6 points).

Solution: (1) Because in the regular quadrangular prism ABCD-a1b1c1d1,

The bottom ABCD is rectangular, AB= 1, BC=2, AA 1=2, and E is the midpoint of the side BB 1.

So s △ a 1ed = 12x2 = 2,

So VA? A 1ED=VE? a 1AD = 13S△a 1ED? AB=23。

(2) take the midpoint f of CC 1 and connect DF, b1f. ..

Because DF∑AE, the angle between DF and B 1D is equal to the angle between AE and b1d.

In △B 1DF,B 1d = 7,DF=2,B 1f = 3,

So cos ∠ b1df = df2+db12? B 1F22DF? DB 1=3 14 14,

So the angle formed by AE and B 1D is arccos 3 14 14.