MHT CET202123 Sep 2021Evening ShiftMathematicsProperties of TrianglesActual
In a triangle A B C , with usual notations a=2, b=3, c=5 , then A a + B b + C c =
Options
- A19 30
- B19 16
- C23 60
- D38 35
Correct answer
A. 19 30
Step-by-step solution
aligned & 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+c^2+a^2-b^2+a^2+b^2-c^2 2 a b c & = a^2+b^2+c^2 2 a b c = 4+9+25 2(2)(3)(5) = 38 60 = 19 30 aligned