Question

In triangle abc ab is the greatest side. Prove that angle C > 60.

Answer 1

AB is the longest side

Therefore,
Angle sum of a triangle is 180°

Therefore, the largest angle should be greater than 60°

Suppose A=30 ,B=70 , C=?

A+B+C=180°
30+70+C=180
C=80>60°
AB is the longest side and angle opposite to longer side is greater
80 is greatest