JEE Main201911 Jan 2019Evening ShiftMathematicsProperties of TrianglesActual
Given b + c 11 = c + a 12 = a + b 13 for a ABC with usual notation. If A = B = C , then the ordered triad ( , , ) has a value
Options
- A(7,19,25)
- B(3,4,5)
- C(5,12,13)
- D(19,7,25)
Correct answer
A. (7,19,25)
Step-by-step solution
Let b+c 11 = c+a 12 = a+b 13 =k (Say). b+c=11 k, c+a=12 k, a+b=13 k a+b+c=18 k a=7 k, b=6 k and c=5 k A= 36 k²+25 k²-49 k² 2.30 k² = 1 5 and B= 49 k²+25 k²-36 k² 2.35 k² = 19 35 and C= 49 k²+36 k²-25 k² 2.42 k² = 5 7 A: B: C=7: 19: 25 A 7 = B 19 = C 25 Hence, required ordered triplet is (7,19,25)