(20 10? Xinxiang No.1 model) In the reconstruction of the old city of our city, a chimney AB (pictured) will be demolished, and the chimney will be measured at the top C of the building CD just west of the chimney. Solution: (1) as shown in the figure. (3 points)

(2) This big tree will not be hit by an inclined chimney. (4 points)

∫ In RT△AGC, ∠ ACG = 45.

∴ Ag = CG = DB = 2 1 (m). (5 points)

In Rt△BCG, BG = CG× tan30 = db× tan30 = 21× 33 = 73. (m)

∴ The height of the chimney AB = 21+73 ≈ 33.124 (m). (8 points)

∫33. 124m < 35m。

This big tree won't be hit by an inclined chimney. (9 points)