Current location - Training Enrollment Network - Mathematics courses - 20 12 The answer in the ninth grade math textbook is P39, the second question of Beijing Normal University Edition. The question of finding the point F on the bisector of the angle should be answered
20 12 The answer in the ninth grade math textbook is P39, the second question of Beijing Normal University Edition. The question of finding the point F on the bisector of the angle should be answered
20 12 The answer in the ninth grade math textbook is P39, the second question of Beijing Normal University Edition. The question of finding the point F on the bisector of the angle should be answered in detail. Why will this be proved? 2. Proof: as shown in Figure F-5.

FG⊥AD at point g, FM⊥BC at point m, FN⊥AE at point n,

∵∠ 1=∠2,

∴GF=MF

∫∠3 =∠4

∴MF=FN

∴GF=FN

Point F is on the bisector of ∠DAE.

3. Prove that (1)∵PC⊥OA is at point C and PD⊥OB is at point D,

∴∠OCP=ODP=90

∠∠AOP =∠BOP,OP = OP。

∴△OCP=△ODP(AAS)

∴OC=OD

(2), OC = OD, and OP is the bisector of ∠AOB.

Perpendicular bisector whose op is CD.