MHT CET202522 Apr 2025Evening ShiftMathematicsProperties of TrianglesActual
In a triangle ABC with usual notations if, A 2 = b+c a , then the triangle A B C is
Options
- Aan isosceles triangle.
- Ban equilateral triangle.
- Ca right angled triangle.
- Dan obtuse angled triangle.
Correct answer
C. a right angled triangle.
Step-by-step solution
Given the condition in triangle ABC: A 2 = b + c a . Using the Law of Sines, a = 2R A , b = 2R B , c = 2R C , substitute into the equation: A 2 = B + C A . Apply sum-to-product and double-angle identities: B + C = 2 ( B + C 2 ) ( B - C 2 ) and A = 2 A 2 A 2 . From the angle sum A + B + C = , note that B + C 2 = - A 2 = 2 - A 2 , so ( B + C 2 ) = A 2 . Substitute and simplify: A 2 = 2 A 2 ( B - C 2 ) 2 A 2 A 2 = ( B - C 2 ) A 2 . Since A 2 = A 2 A 2 , equate: A 2 = ( B - C 2 ) . Given the domain constraints, A 2 = B