Applied Science - Science and Math (2C) Pre Lab
 OBJECTIVES: Investigating symmetry. Comparing symmetry of geometric shapes. VOCABULARY: bilateral cubic hexagonal pattern pentagonal radial symmetry MATERIALS: construction sets to help illustrate symmetry (i.e. Googoplex,  Zometool) Students classify different objects into their symmetry.
 BACKGROUND: Symmetry refers to, "the correspondence in size, form, and arrangement of parts on opposite sides of a plane, line, or point." If you look at the word in the dictionary, you will notice a list of definitions for subjects as diverse as geometry, botany, physiology, chemistry, and geology.  Symmetry can refer to two dimensional as well as three dimensional objects.  Some objects can have one or more symmetries.  In nature symmetry is not always perfect, but the terms are still applicable.   Bilateral symmetry is when one side looks like the other or is a mirror imagine.  Humans are bilaterally symmetrical .  If you make an imaginary line from the head to the ground; one side basically looks like the other.  However if you look at the organs inside a human, they are not bilaterally arranged.      Radial symmetry is when all segments are equal that radiate from a point.  A ball or a circle has radial symmetry.  Note that all objects that have radial symmetry also have bilateral symmetry. Pentagonal symmetry reflects a five-part symmetry.  The echinoderms (sea stars, sand dollars) are an excellent example of pentagonal symmetry.  This is easily recognized as a “star” shape.  Internally, echinoderms also have a five part symmetry. There are other ways of dissecting symmetry including hexagonal symmetry (six-part) and cubic symmetry (three-dimensional square).  Symmetry is all around us if we just look and describe. PROCEDURE: The objectives of this week's activities are to illustrate the difference between symmetry  in nature.  The first exposure to these concepts will give students a new vocabulary power to describe and observe the world.  Go over each of the above vocabulary words and illustrate with examples.  Reinforce the types of symmetry so children can learn by experience.  Listed below are a few ideas.      Use a  construction type set that can help illustrate the different types of symmetry.  Include bilateral, radial, pentagonal, hexagonal, and cubic.  Construct these examples  before class so you can show students.   Draw the different types of symmetry on the board and have students think of examples.   Reinforce the words using a model and do not expect students to learn with just one introduction.      Students will continually use these terms throughout this program.  This is only an introduction to symmetry.  Start them off right!    The worksheet will help illustrate different types of symmetry using models.  Look at your worksheet and have students color in the different types of symmetries.  If you have any of the construction type kits or paper models you may want students to make one of the different shapes.  1. bilateral symmetry = one side looks like other  2. radial symmetry = radiate from a point  3. pentagonal symmetry = 5 part symmetry  4. hexagonal symmetry = 6 part symmetry  5. cubic symmetry = 4 part symmetry