AP EAMCET201822 Apr 2018Evening ShiftMathematicsProperties of TrianglesActual
In A B C , if a=3, b=4, c=6 , then A 2 + B 2 + C 2 A+ B+ C =
Options
- A13 61
- B169 61
- C61 169
- D61 13
Correct answer
B. 169 61
Step-by-step solution
aligned A 2 + B 2 + & C 2 = s(s-a) & + s(s-b) + s(s-c) & = S [3 S-(a+b+c)] & = S (S)= S^2 = (a+b+c)^2 4 aligned Now, aligned & Now, A+ B+ C= A A + B B + C C &= b^2+c^2-a^2 2 b c A + c^2+a^2-b^2 2 a c B + a^2+b^2-c^2 2 a b C &= b^2+c^2-a^2 4 + c^2+a^2-b^2 4 + a^2+b^2-c^2 4 &= a^2+b^2+c^2 4 & A 2 + B 2 + C 2 A+ B+ C = (a+b+c)^2 a^2+b^2+c^2 &= (3+4+6)^2 9+16+36 = 169 61 . aligned