AP EAMCET202317 May 2023Morning ShiftMathematicsProperties of TrianglesActual
In ABC , if C =90^ , then ( r ₁- r ₃ r ₁ ) ( r ₂- r ₃ r ₂ )=
Options
- A1
- B3
- C4
- D2
Correct answer
D. 2
Step-by-step solution
aligned & C=90^ C^2=a^2+b^2 & Now, ( r₁-r₃ r₁ ) ( r₂-r₃ r₂ )= s-a - s-c s-a s-b - s-c s-b & = s-c-(s-a) s-c s-c-(s-b) s-c & = a-c s-c b-c s-c = a b-a c-b c+c^2 ( a+b+c 2 -c )^2 & =4 (a b-a c-b c+a^2+b^2 ) (a+b-c)^2 & =4 (a b-a c-b c+a^2+b^2 ) a^2+b^2+c^2+2 a b-2 b c-2 c a & =4 a^2+b^2+a b-a c-b c 2 (a^2+b^2 )+2 a b-2 b c-2 c a =2 c^2=a^2+b^2 aligned