This is the seventh in a series of videos about the graph data structure. It describes a Visual Basic.NET implementation of the A* path-finding algorithm (pronounced A Star) for a weighted, undirected graph. The algorithm was described in a previous video. The A* pathfinding algorithm, and its numerous variations, is widely used in applications such as games programming, natural language processing, financial trading systems, town planning and even space exploration. This implementation makes use of a graph class and a separate vertex class. The vertex class includes properties specifically for use by the A* program. The A* algorithm is implemented as a method of the graph class. This can be considered a partially object oriented approach, because the edges of the graph are represented by an adjacency matrix which is a two dimensional array of integers. Vertices are therefore often referenced by index numbers. This implementation makes use Manhattan distances for the heuristic, but it shows that an alternative heuristic, in this case straight line (Euclidean) distances, may produce a different result.