In this video, let's discuss the external angle dissector theorem.
All right, so over here we have a triangle and side beauty is extended to T. Right now.
We know that this angle over here, that's angle t v Q is an external angle.
All right, now let's construct the efforts that this angle over here is equal to this angle or here
that is D.F. is the angle by sector of angle dequeue.
All right.
So these two angles are equal.
Now, it's easier to write the ratio as per the external angle bisecting theorem if you imagine the
external angle by sector to be an internal angle by dissector.
So that's a trick to write the ratio correctly.
So let's quickly imagine that D.F. was the internal angle by sector over here.
Now we know how to write the ratio in this case.
Right.
The ratio would be pretty by dequeue is equal to PEF by RFQ.
So let me write that over here.
We have already seen that right now over here, having got the ratio, we just need to remove this part
and keep the angle by sector as the external angle by sector.
And this ratio is the correct ratio over here as well that is very divided by dequeue will be equal
to P F, divided by F Q and that is the external angle by sector here.