Solution: 1 From the meaning of the question, we can know that ∠ BCE' = 15, and the intersection of ED' and BC is g, then ∠ d 'gb =180-∠ e-∠ BCE' = 65436.

2. The result of the first question shows that O is the midpoint of AB, so AO=CO=BO=3.

So D'O=4, ∠ aod' = 90, so we get AD'=5 from Pythagorean theorem.

3. After rotation, you can get ∠ BCE'' = ∠ CBE'' = 45, and DE'' intersects BC in G', then CE'' = BE'' = 7/2, CG' 2 = 49/2;

BC 2 =18, so BC < CG', so point B is inside the triangle.