In a ΔPQR, I is the in-centre and PI↔ cuts QR¯ at S . If Q=(–1, 2), R=(9, 7), PQ=14, PR=21 then S is
(5, 5)
(4, 92)
(−215, −85)
(3, 4)
Q(−1, 2), R(9, 7)
QR100+25=25
PI cuts QR¯ at 's'
In the ratioPQ:PR=14:21=2:3
S=2R+3Q2+3=(18, 14)+(−3, 6)5=(3, 4)