Don't show hidden triangles in Object Mode In Edit Mode, I've hidden some triangles. But when I switch back to Object Mode, the entire mesh is rendered. Is there a way to not render hidden triangles when in Object Mode?
You could assign the vertices to a vertex group and then use a mask modifier to hide the vertices.

By adjusting the visibility settings of the modifier you can also use it to hide the vertices in edit mode or only hide them when rendering.