Which pattern can be laid out using radial line development?

Radial line development is a method used in sheet metal layout, particularly for creating patterns for cylindrical shapes, such as cones and elbows. The correct choice involves the on-center taper or right cone, which showcases how radial line development is applied.

In radial line development, lines are drawn from a central point (the cone's apex) at various angles to represent the sloped surfaces of the taper or cone. The method allows for accurate representation of the changing dimensions as you move along the taper, making it possible to create precise patterns for fabrication. This technique is particularly useful when dealing with the geometry of a cone, as it simplifies the process of translating the three-dimensional shape into a two-dimensional pattern that can be cut from sheet metal.

The other choices, while also important in sheet metal work, do not utilize radial line development in the same way. Curved elbows generally require either a conical or an arc method for development, square duct transitions usually rely on parallel line development, and rectangular duct fittings often utilize rectangular or trapezoidal geometric principles for accurate layout and cutting. Each of these methods has its own set of established techniques, but when specifically discussing radial line development, the on-center taper or right cone is the fitting that aligns with the principles of