Geodesic paths and distances on meshes are used for many applications such as parameterization, remeshing, mesh segmentation, and simulations of natural phenomena. Noble works to compute shortest geodesic paths have been published. In this paper, we present a new approach to compute the straightest path from a source to one or more vertices on a manifold mesh with a boundary. A cutting plane with a source and a destination vertex is first defined. Then the straightest path between these two vertices is created by intersecting the cutting plane with faces on the mesh. We demonstrate that our straightest path algorithm contributes to reducing distortion in a shape-preserving linear parameterization by generating a measured boundary.