MHT CET202618 April 2026Evening ShiftMathematicsProperties of TrianglesActual
In ABC , with usual notations, if denotes the area of triangle ABC then the value of 2s(b+c-a) ( A 2 ) is equal to
Options
- A2
- B3
- C4
Correct answer
3
Step-by-step solution
We know that the semi-perimeter of a triangle is given by s = a+b+c 2 , which implies 2s = a+b+c . The term b+c-a can be rewritten as: b+c-a = (a+b+c) - 2a = 2s - 2a = 2(s-a) Substituting this into the given expression, we get: 2s(b+c-a) ( A 2 ) = 2s(2(s-a)) ( A 2 ) = 4s(s-a) ( A 2 ) Using the half-angle formula for tangents in a triangle: ( A 2 ) = (s-b)(s-c) s(s-a) Multiplying the numerator and the denominator inside the square root by s(s-a) gives: ( A 2 ) = s(s-a)(s-b)(s-c) s(s-a) By Heron's formula, the area o