As shown in the figure, if the quadrilateral ABCD is trapezoid, ad ‖ BC, CA is bisector of ∠ BCD, and ab ⊥ AC, ab = 4, ad = 6, then tanb = () A. 23B. 22C. 114D. 554

As shown in the figure, if the quadrilateral ABCD is trapezoid, ad ‖ BC, CA is bisector of ∠ BCD, and ab ⊥ AC, ab = 4, ad = 6, then tanb = () A. 23B. 22C. 114D. 554

∫ CA is the bisector of ∠ BCD, ∫ DCA = ∠ ACB, and ∫ ad ∥ BC, ∫ ACB = ∠ CAD, ∫ DAC = ∠ DCA, ∫ Da = DC, passing through point D as de ∥ AB, intersecting AC at point F, intersecting BC at point E, ∫ ab ⊥ AC, ≁ de ⊥ AC (the property of isosceles triangle three lines in one), ∫ point F is the midpoint of AC, ∫ AF = CF, ∫ EF is the median line of △ cab, ∫ EF = 12ab = 2, ∫ AFFC = dfef = 1, ≁ DF = EF = 2, at RT △ ADF If AF = ad2 − df2 = 42, then AC = 2AF = 82, tanb = acab = 824 = 22