What is the minimum number of straight line segments used to form the following figure?

14

The number of minimum line segments can be calculated by counting the longest line segments :

The outer square is made out of 4 line segments 

The number of such line segments = 5

Similarly, in the opposite direction same number of line segments were made 

This makes up the minimum number of line segments that make up this figure = 4 + 5 + 5 = 14