Problem:
In β³ABC shown in the figure, AB=7,BC=8,CA=9, and AH is an altitude. Points D and E lie on sides AC and AB, respectively, so that BD and CE are angle bisectors, intersecting AH at Q and P, respectively. What is PQ?
Answer Choices:
A. 1
B. 85β3β
C. 54β2β
D. 158β5β
E. 56β Solution:
Let x=BH. Then CH=8βx and AH2=72βx2=92β(8βx)2, so x=2 and AH=45β. By the Angle Bisector Theorem in β³ACH,PHAPβ=CHCAβ=69β, so AP=53βAH. Similarly, by the Angle Bisector Theorem in β³ABH,QHAQβ=BHBAβ=27β, so AQ=97βAH. Then PQ=AQβAP=(97ββ53β)AH=458β45β=158β5ββ.