7. Circles seen in perspective appear as ellipses.

The ellipse may be

sized and placed in perspective by constructing it within a square.

The

reason the circle in perspective is drawn with the aid of the square is that

while there are no direct measurements on a curve, vanishing points are

easily determined for the square, and proportions of the curves can easily

be seen with the square.

Figure 2-8.

Layout for a circle in perspective