# How we will prove that the sum of the measure of any two sides of a triangleis greater than the third side

2
by marini

• Brainly User
2014-07-20T15:32:35+05:30

We can extend BA past A into a straight line.

There exists a point D such that DA = CA.

Therefore, \angle ADC = \angle ACD because isosceles triangle have two equal angles.

Thus, \angle BCD > \angle BDC by Euclid's fifth common notion.

Since \triangle DCB is a triangle having \angle BCD greater than \angle BDC, this means that BD > BC.