Perpendicular is the shortest distance

Classical Mechanics Level 5

Deepanshu and Mvs Saketh are moving along 2 long straight lines, in same plane , with same speed = $20 ~ cm/s$ . The angle between the 2 lines is $60^{\circ}$ , and their intersection point is O. At a certain moment, Deepanshu and Mvs Saketh are located at distances 3m and 4m from O , and are moving towards O . Find the shortest distance between them in centimetres.