Fig. 6
These three are the most usual figures, but it is easy to draw any number of sides to your polygon you may require.
First draw a circle, and lay off any diameter A B. Divide A B into as many equal parts as you want sides (in Fig. 5 it is five, as that is the most usual number required, but it may be seven or nine or any other number). From A and B with radius A B describe the arcs cutting each other at C. From C draw a line to figure 2 on the diagonal and produce it till it cuts the circle at D. Then from D with radius A D cut the circle at 2´, from 2´ cut it at 3´, and so on, and join 1´ 2´, 2´ 3´, 3´ 4´, 4´ 5´.
With a circle, too, it is easy to lay out a star bed with four, six, or eight points (Fig. 6), or a half moon.
Rectangular beds are also most easily set out by means of a circle.
In a diamond the line should bisect the diagonal.
The only other shape in general use is an oval, and this is not built up on the circle. First determine the length and breadth A B, C D (Fig. 7). Bisect A B and make C D perpendicular to it at the point of bisection O. From C with radius O A, cut A B in E F. These points are the form of the oval.
Fig. 7