Understand symmetrical graphics and draw the class emblem of axisymmetric graphics. The specific steps are as follows:

1. Draw a circle, find out the key points of the graph and mark them with serial numbers.

2. Find the distance between the graphic point and the symmetry axis, and connect the serial number ① ②.

3. Then connect the serial numbers ① ③ in the figure.

4. Connect the serial number ② ③ at two points.

5. Finally, connect points ① and ④ with dotted lines to confirm the symmetry axis.

Axisymmetric graph theorem;

Theorem 1: Two graphs symmetric about a straight line are conformal.

Theorem 2: If two figures are symmetrical about a straight line, then the symmetry axis is the perpendicular line connecting the corresponding points.

Theorem 3: Two figures are symmetrical about a straight line. If the axis of symmetry intersects the extension lines of two symmetrical line segments, the intersection point is on the axis of symmetry.

Theorem 3 Inverse Theorem: If the straight line connecting the corresponding points of two graphs is vertically bisected by the same straight line, then the two graphs are symmetrical about this straight line.