1

The triangle DEF circumscribes the three escribed circles of the triangle ABC. I have to prove that

$$\dfrac{EF}{a \cos A} = \dfrac{FD}{b \cos B}= \dfrac{DE}{c \cos C}.$$ Also, point D is opposite to A. E is opposite to B. F is opposite to C

I am not able to find the angles of the triangle DEF. Help me

isaac ismav
  • 147
  • Do you have any graph? Maybe of interest https://math.stackexchange.com/questions/275167/a-geometry-problem-about-inscribed-and-circumscribed-circle-radius?rq=1 – cgiovanardi Jun 20 '17 at 22:39

0 Answers0