In ∆ABC, P is a point on AB such that PB : AP = 3 : 4 and PQ is parallel to AC. If AR and QS are perpendicular to PC and QS = 9 cm, what is the length (in cm) of AR?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 21.
As seen in the figure
In △ARC and △QSP
∠ARC = ∠PSQ = 90°
∠CAP = ∠QPB (Since PQ and AC are parallel)
Hence, △ARC ~ △QSP (AA criterion)
⇒ =
Now since △BPQ ~ △BAC,
⇒ =
Hence, =
Hence AR = 21 cm.