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Grade 12Trigonometry

If in a triangle ABC, the exradii r1, r2, r3 are such that r1=2r2=3r3 then prove that the triangle is right angled . Also find a:b:c.

Profile image of Nirabhra  Agrawal
15 Years agoGrade 12
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3 Answers

Profile image of SAGAR SINGH - IIT DELHI
15 Years ago
Dear student,
r1=2r2=3r3
Then
r1/6=r2/3=r3/2 =k using ratios
Hence r1=6k,
r2=3k
r3=2k
Hence using the property of solution of trianle the required triangle is equilateral.
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Askiitians Expert
Sagar Singh
B.Tech, IIT Delhi
Profile image of Nirabhra  Agrawal
15 Years ago

Dear Sagar ji, 

Will you please solve this question in full as I could not prove the required results with the hints given by you. Few days back I had called and requested you for the same.Thanks.

G P Agrawal

F/o Nirabhra Agrawal

Profile image of Shashank agrawal
9 Years ago
r1=6r by using a property 1/r1+1/r2+1/r3=1/rAs,r1=stanA/2, r=(s-a)tanA/2 ,So,s/(s-a)=6a=5s/6Similarly,b=2s/3,c=s/2,So,triangle is right angled at A