Deleting Vertices and triangles from a mesh

i’m trying to cut this mesh from one side of a Plane( this plane acts as blade),
I can use the function Plane.GetSide to determine if a particular vertex of mesh is supposed to be deleted or not.
But the problem is, i can delete the Vertex from Vertices array because Triangle array will be confused by it.

For now, i’m setting Vertices = New Vector(1000,1000,1000).
Please help me on how to delete those vertices and triangles.

Hi. Did u found any solution for this problem?