Question

If in an isosceles triangle base is the shortest side then show that the vertical angle is less than 60°

Answer 1

x+x+60=180
2x=180-60
2x=120
x=120/2
=60

Answer 2

$x + x + 60 = 180 \\ 2x = 180 - 60 \\ 2x = 120 \\ x = 120 \div 2 \\ = 60$