During the coronavirus disease 2019 (COVID-19), it was a difficult task to ensure that people maintain the required social distance while standing in a queue or gathering around public offices and places, like banks, govt. offices, airports, railway stations, temples, churches, mosques etc. This problem not only violates the necessity of social distancing, but also escalates fear, concern, and risk, among and for people standing in a queue and the person or people providing service in the vicinity. The authorities can monitor and control the social distancing rule being followed by persons in the crowd at public places, if some automatic system is available to make them alert. The purpose of this research is to present an automatic monitoring system to calculate distance between two persons in the given scene and produce an alert if social distancing norms are violated. The authorities will come across an alert and they will initiate an appropriate action to control the situation. The system takes live video footage as input and calculate the distance between persons and alert the authorities in output video using colour bounding boxes. The persons appearing in the footage are standing with different angles between them, such as 90°, 30°, 120°, 180°. The results are 90 percent accurate. Thus the proposed system can be used to monitor social distancing at public places. [ABSTRACT FROM AUTHOR]