A circular arc is a continuous portion of a circle’s circumference. In letter design, arcs provide curved sections that can be scaled more reliably than collections of straight lines. section 2.1
Building a letter C
A letter C can be assembled from straight lines and circular arcs. This works for a simple curve, but an ampersand or another complicated letter may need many different curves joined smoothly. section 2.1
Circular arcs are useful but limited:
- They are easy to draw with a compass and suit simple letter forms. section 2.1
- They cannot represent every curve, so complex shapes may require French curves or Bézier curves. section 2.1 section 2.3
- Bézier curves can closely approximate a circle or arc, but cannot represent one exactly; four curves approximate a full circle. section 2.3
Figure 2.1 The letter C composed of only straight lines and circular arcs
Compare a C made from straight lines and circular arcs to see why curved primitives matter for scalable letter forms. section 2.1
