Page 16 - Math 21 Module_Chapter One
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*The opposite of symmetry is asymmetry.
1. Reflection (bilateral) symmetry – a symmetry in which the left and right
sides of the organism can be divided into approximately mirror image or
reflection of each other along the midline. The midline is also called the central
line or the mirror line. Symmetry exists in living things such as in insects, animals,
plants, flowers and others. Animals have mainly bilateral or vertical symmetry,
even leaves of plants and some flowers such as orchids.
2. Radial Symmetry (or rotational symmetry) – is a symmetry around a
fixed point which is known as the center. Radial symmetry can be classified as
either cyclic or dihedral.
In cyclic symmetry, each rotation will have an angle of 360/n and is denoted
by Cn, where n is the number of rotations. For example, an object having C3
symmetry would have three rotations of 120 degrees.
