Question -
Answer -
In the given problem, BP and CP arethe internal bisectors of
respectively. Also, BQ and CQ arethe external bisectors of
respectively. Here, we need toprove:

We know that if the bisectors of angles
and
of ΔABC meetat a point O then

Thus, in ΔABC
……(1)
Also, using the theorem, “if the sides AB and AC of a ΔABC are produced, and theexternal bisectors of
and
meet at O, then 
Thus, ΔABC
∠BQC=90°−12∠A ......(2)∠BQC=90°-12∠A ......2
Adding (1) and (2), we get

Thus, 
Hence proved.