HP 5961-0509 manual Counting the Points in a Circle or Arc, 21-16The Polygon Group

The following shape has seven points.

Figure 21-11

Counting the Points in a Circle or Arc

When a circle or arc defines a polygon, the number of points depends on the number of chords in the arc. There is always one more point than the number of chords, because the starting location is counted again as the ending location. Use the following formula to determine the number of points used to draw a circle or arc:

	Using this formula, a full circle with the default chord angle of 5°
	consists of 73 points (360/5 + 1 = 73), and a 45° arc with a chord
	angle of 3° consists of 16 points (45/3 + 1 = 16).
Notes	If the chord angle does not divide evenly into the arc, round up to the
	next integer before adding one: 45/2 + 1 = 23 + 1 = 24.
	In polygon mode, the smaller a circle’s chord angle, the more chords
	will be stored in the polygon buffer to draw it.

21-16The Polygon Group EN