M is a point on side BC of a triangle ABC such that AM is the bisector of BAC. Is it true to say that perimeter of the triangle is greater than 2AM ? Give reason for your answer.
True
Solution.
Perimeter of ABC = AB + BC + AC
In AMB and AMC
We know that sum of two sides of a triangle is greater than third side.
AB + BM > AM ......(1)
and AC + MC > AM ......(2)
By adding (1) and (2) equation
AB + BM + MC + AC > 2AM
Since, BC = BM + MC
AB + BC + AC > 2AM
=> Perimeter of ABC > 2AM
Hence the given statement is true.