In wireless Sensor Networks (WSNs), the coverage hole is obtained due to random deployment of sensor nodes over the dense forest and terrain lands. Coverage holes are the fundamental issue which affects the quality of the WSNs. Only if the coverage holes are detected, they are patched using sensor nodes known as healing. It is not possible to find the coverage holes manually. Therefore the coverage hole, detecting and healing have become a major challenges in order to achieve the best coverage of the WSNs. For this purpose, we proposed the algorithm named as a Delaunay Triangulation merged with the virtual edge based method; it helps to detect the coverage holes in WSNs. The algorithm helps to detect the accurate size of the coverage holes when compared to the existing tree based method. Experimental results reveal that the proposed method detects the coverage hole more accurately and finally patch the coverage holes with minimum number of nodes. © 2017 IEEE.