Biology
Definitions

# What are 3 types of symmetry? ###### 2017-09-05 10:05:33

Radial symmetry is rotational symmetry around a fixed point known as the center. Radial symmetry can be classified as either cyclic or dihedral.

Cyclic symmetries are represented with the notation Cn, where n is the number of rotations. Each rotation will have an angle of 360/n. For example, an object having C3 symmetry would have three rotations of 120 degrees.

Dihedral symmetries differ from cyclic ones in that they have reflection symmetries in addition to rotational symmetry. Dihedral symmetries are represented with the notation Dn where n represents the number of rotations, as well as the number of reflection mirrors present. Each rotation angle will be equal to 360/n degrees and the angle between each mirror will be 180/n degrees. An object with D4 symmetry would have four rotations, each of 90 degrees, and four reflection mirrors, with each angle between them being 45 degrees.

Bilateral Symmetry

Bilateral symmetry is symmetry across a line of reflection. Are people symmetric? We think we are, but upon closer analysis, we are less symmetric than we think. The more simple the creature (ants --> elephants), the more likeley it is that it will be perfectly symmetric.

We took two professors, cut and pasted half of their head in Photoshop, and flipped that half horizontally. We then aligned the two halves so that it came closest ro resembling a human head. You be the judge on how good of a job we did and how symmetric people around us are in general ...

Asymmetrical Symmetry

Asymmetry is the absence of, or a violation of, symmetry. Copyright © 2020 Multiply Media, LLC. All Rights Reserved. The material on this site can not be reproduced, distributed, transmitted, cached or otherwise used, except with prior written permission of Multiply.