Which statement is true when using Resize Chamfer on selected faces?

The statement that resizing a chamfer must have a constant width is correct because the Resize Chamfer tool in Siemens NX is designed to maintain a uniform width across the selected edges during the resizing process. When you select a chamfer to resize, it is important that the width remains consistent, which ensures that the geometry remains well-defined and adheres to standard modeling practices. This characteristic helps avoid complications that can arise from variable widths, such as unintended changes in the profile of the part or issues during manufacturing or assembly.

The concept of constant width is fundamental to chamfer design, as changes in width can lead to inconsistencies in the finished part and affect its fit and function. This principle is an essential aspect of solid modeling in CAD applications, including Siemens NX, promoting precision and predictability in the modifications of 3D geometry.