P is any point in the interior of triangle ABC. Prove that AB+AC>BP+CP.
Answer:
- Let us first mark the point P in the interior of △ABC.
- Now, let us join line BP and CP and produce CP to meet AB at Q.
- We know that the sum of two sides of a triangle is greater than the third side.
Thus in △ACQ, we have AC+AQ>CQ⟹AC+AQ>CP+PQ…(1) Similarly in △BPQ, we have BQ+PQ>BP…(2) - By adding (1) and (2), we get:AC+AQ+BQ+PQ>CP+PQ+BP⟹AC+AQ+BQ>CP+BP[Subtrating PQ from both the sides]⟹AC+AB>CP+BP[As AQ + BQ = AB]
- Thus, we have AC+AB>CP+BP.