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The circular Line.
The mother draws before the child a circle, and says, this line, pointing to 5, is called a circular line; and the interior space, pointing to a, a circle.
Mother. Can you draw a circular line? Draw four circular lines. The drawing these lines must be practised from right to left, and from left to right. The mother makes a point in the middle of the circle, saying, this point is called the centre of the circle. Draw a circular line, and try to find the centre.
The Curve Line or Arch.
Mother. This line is called a curve. Draw three, four, &c. curves or arches. The mother, pointing to b, says, ^-^r-v^ this is the convex, and pointing to a, this is the concave side of the curve or arch. Show me the convex side. Can you point out the concave side?
Mother. Can you draw two circular parallel lines? If the child cannot do it, the mother draws them.
Draw two parallel curves or arches; three not parallel curves; three parallel, and two not parallel curves, &c.
The mother draws the two angles, a and b, saying, the angle a is formed of two concave sides, and is called a concave angle: b formed of two convex
sides, and is called a convex angle. The third is composed of a convex and a concave side, and is therefore called a mixed angle.
Draw concave, convex, and mixed angles.
Draw three concave, four convex, and two mixed angles.
Represent every thing you know of the circular line on your slate.
Of two-angled Curve-lined Figures.
Mother. Here are two-angled figures: the first composed of mixed angles;
the second of convex;
and the third of concave angles.
Draw a figure with two concave angles.
Draw three two-angled figures, with convex sides, &c.