study material-mathematics-trignometry
solution-of-triangles-8
Hard
Q-1: The internal bisectors of the angles of the DABC meet the sides BC, CA and AB at P, Q, and R respectively. Show that the area of the DPQR is equal to
Solution:
Let the bisector of the angles meet at
Q=ÐBIP-ÐBID =
Fig (24)
Now from DDIP,
Q-2: Show that the DABC is equilateral if its circumradius is double of the inradius.
Solution:
Here R=2r (given) .We know that,
So, triangle is equilateral.