there ar two points D and E on side AB of triangle ABC such that AD=BE. IF DP IS PARALLEL TO BC AND EQ IS PARALLEL TO AC, THEN PROVE THAT PQ IS PARALLEL TO AB

given: ABC is a triangle. AD = BE.

DP || BC and EQ || AC

TPT: PQ || AB

proof:

in the triangles ADP and EBQ;

AD = BE (given)

∠DAP = ∠BEQ [corresponding interior angles]

∠ADP = ∠EBQ [corresponding interior angles]

therefore by ASA congruency triangle ΔADP ≡ ΔEBQ

thus by CPCT : PD = BQ..........(1)

and PD || BQ [given]......(2)

since one pair of opposite side are equal and parallel.

therefore quadrilateral DPQB is a parallelogram and

 PQ || DB

i.e. PQ || AB

which is the required result.

hope this helps you.

cheers!!

  • 198
ACC TO THE QUESTION:
BY BPT WE HAVE AD/DB = AP/PC AND SIMILARLY BQ/QC = BE/EA
IF AD = BE THEN DB IS ALSO EQUAL TO AE THUS AD/DB = BE/EA SO WE GET AP/PC = BQ/QC BY CONVERSE OF BPT PQ IS PARALLEL TO AB
  • 2
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