To indicate an angled surface and make that surface parallel to a surface plate, a machinist would use a?

A sine plate is the correct choice for indicating an angled surface and making that surface parallel to a surface plate. This tool is designed to set or measure specific angles accurately. The sine plate contains precision-ground surfaces and slots that hold blocks, allowing a machinist to create or measure angles based on the sine function of the desired angle.

When using a sine plate, a machinist can adjust the angle precisely to align with the surface plate, which is crucial for ensuring that the workpiece is set correctly for operations such as machining or inspection. This ability to establish and confirm angles is essential in maintaining adherence to tolerance requirements in various machining tasks.

In contrast, while a level is useful for checking flatness, it does not provide the precision required for setting angles. An angle plate may assist in holding workpieces at specific angles, but it does not facilitate fine adjustments in the same way as a sine plate. A V-block is designed for holding cylindrical workpieces securely, but it is not suitable for indicating or setting angles. Each tool has unique applications, but for the specific purpose of indicating and aligning an angled surface, the sine plate is the most appropriate choice.