Final answer:
The purpose of using dimensions in arcs, circles, and to show detail is to provide information about their shape and size.
Step-by-step explanation:
The purpose of using dimensions in arcs, circles, and to show detail is primarily to provide information about the shape and size of the arcs and circles (Option 2). Dimensions help us understand the characteristics of arcs and circles, such as their radius, diameter, and circumference. By including dimensions, we can accurately represent and analyze these geometric figures.