Which type of arc can directly transition from a line during sketching?

The Tangent Arc is the correct choice because it allows for a seamless transition from a line segment to the arc. When you sketch a Tangent Arc, it connects to the end of the line at a point where the two geometries meet perfectly, creating a continuous flow without any angular discrepancy. This characteristic is particularly useful when designing profiles or features that require smooth, curved transitions directly from straight edges.

On the other hand, the other types of arcs have specific constraints or ways in which they engage with lines. The 3 Point Arc requires you to define three distinct points, which can make it less efficient for directly transitioning from a line. The Center Point Arc is defined by a center point and the radius, which means that you would not be directly transitioning from a line but rather creating an arc based on a central reference. The Equal Radius Arc, while it suggests a relationship in radius, still can pose similar limitations as it doesn't inherently connect to a line without additional constraints or manipulations. Thus, for directly transitioning from a line while sketching, the Tangent Arc is specifically designed for that purpose.