**PRIN. OF DRAFTING AND SHOP DRAWINGS - OD1641 - LESSON 1/TASK 1**

*To a draftsman, the accuracy of a curve is a function of the number of points used*

*to define the curve.*

To draw a perfectly accurate curve would require an infinite number of points. To

do this is not only impossible, it is also impractical.

Most curves may be very

closely approximated by a finite number of points, and it is up to the draftsman to

determine what level of accuracy is required and how many points he needs to

achieve this level. Circles and perfect arcs are exceptions to the axioms because

they may be drawn with perfect accuracy using a compass.

Figure 14 is an example of the curved line projection problem, while figure 15 (on

the following page) offers the solution to this problem.

FIGURE 14.

CURVED LINE PROJECTION

PROBLEM.

**14**