Tessellations Rotation Translation Reflection Assessment Teacher’s Page Click on one of the pictures to learn more!! Tessellations • A tessellation is another name for a tiling • Tessellations are made up of regular polygons that are repeated over and over again to cover an entire plane • They cannot have any gaps or overlaps • Every vertex of a tessellation must be the same, and the angles of the vertices must add up to 360 degrees Regular Tessellations Semi-Regular Tessellations Click on one of the two types of tessellations to learn more! Main Menu Regular Tessellations • The tessellation must tile a floor completely with no gaps and no overlaps • The tiles must all be the same regular polygon • All the vertex angles must look the same • There are 3 examples of regular tessellations Triangles Squares Hexagons Click on one of the three shapes to learn more! Go Back Equilateral Triangles • The interior angle of each equilateral triangle is 60 degrees • The vertex angles are 60+60+60+60+60+60= 360 degrees Go Back Squares • The interior angle of a square is 90 degrees • The vertex angels are 90+90+90+90= 360 degrees Go Back Hexagons • The interior angle of each hexagon is 120 degrees • The vertex angles are 120+120+120= 360 degrees Go Back Semi-Regular Tessellations • A semi-regular tessellation is made up by using two or more different regular polygons • The arrangement of polygons at each vertex must still be the same and the vertices must add up to 360 degrees Which of the following are examples of semi-regular tessellations? Click on the ones that you think are the answer to find out! Main Menu Go Back Yes! You are right! This is a semiregular tessellation because it does not have any gaps or overlaps and all of the vertices are the same! Go Back Yes! You are right! This is a semiregular tessellation because it does not have any gaps or overlaps and all of the vertices are the same! Go Back Sorry! Wrong answer This is not a semiregular tessellation because it does not follow the rule that all the vertices must have the same configuration Go Back Translation (Slide) • A translation is another name for a slide • If you move an object from one area to another on a plane without rotating or reflecting it, it is a translation • Every point of the object must move the same distance in the same direction Main Menu Click here for more Practice! Rotation (Turn) • Rotate is another name for turn • Every rotation has a center and an angle Main Menu Click here for more Practice! Reflection (Flip) • Another name for reflection is a flip • The reflected figure is always the same size, it just faces in the other direction • To reflect an object means to produce its mirror image • Every reflection has a mirror line Main Menu Click here for more Practice! Quiz Directions: Write one to two sentences for each of the following questions. Why are the following NOT regular tessellations? 1. 2. Next Create Your Own Tessellation!! Directions: Create your own unique tessellation that includes reflections, rotations, and translations by clicking on the button below. Mark a few places where these things occur in your tessellation. Once you have completed it, print it out and hand it in. Click here to create your own tessellation! Main Menu Teacher’s Page • Lesson Objective: This lesson is geared towards students in the 5th grade. It is designed to help student understand the concept and the process of creating tessellations. The students will learn what a tessellation is, and what the rules for creating a tessellation are. They will also learn what a reflection, rotation, and translation is. They will then use all of the skills that they learned to be assessed by creating their own unique tessellation. Also included in the assessment is a quiz. The rubric for these assessments will be based on how well they answer the quiz questions, and how well they do on creating their own tessellation and identifying where it reflects, rotates, and translates. • NCTM standards: • • • Main Menu •recognize, name, build, draw, compare, and sort two and threedimensional shapes •describe attributes and parts of two and three-dimensional shapes •identify, compare, and analyze attributes of two and threedimensional shapes and develop vocabulary to describe the attributes Teacher’s Page • CT Standards: • Grade 5 #1- The students are able to draw and classify 2dimensional shapes and geometric vocabulary • Grade 5 #6- The students will be able to relate geometric shapes to nature and the real world Lesson Plan – click to see the lesson plan References on next page References • • • • • • • • • • Main Menu http://www.coolmath.com/tesspag1.htm http://mathforum.org/sum95/suzanne/tess.intro.html http://standards.nctm.org/document/appendix/geom.htm http://www.mathsisfun.com/geometry/rotation.html http://www.mathisfun.com/geometry/reflection.html http://www.mathsisfun.com/geometry/translation.html http://library.thinkquest.org/16661/Escher.html Virtual Manipulative websites Google images CT standards