`Circles`

are constructed just like `Ellipses`

, except that
the vertical and horizontal axes are per definition the same, so
there's only one argument for the diameter, instead of two for the
horizontal and vertical axes:

Point P(0, 2, 1); Circle c(P, 3.5, 90, 90); c.draw();

Fig. 35.

This constructor, too, has a corresponding setting function:

Circle c; Point p(-1, 0, 5); for (int i = 0; i < 16; ++i) { c.set(p, 5, i * 22.5, 0, 0, 64); c.draw(); }

Fig. 36.

In the preceding example, the last argument to `set()`

, namely "64",
is for the number of `Points`

used for constructing the perimeter
of the `Circle`

. The default value is 16, however, if it is used,
foreshortening distorts the most nearly horizontal `Circle`

.
Increasing the number of points used improves its appearance. However,
there may be a limit to how much improvement is possible.
See Accuracy.