Serving Up Symmetry

1. Serving Up Symmetry Man made and natural patterns made to order!

2. Symmetry What am I Learning Today? How will I show that I learned it? Determine and explain lines of symmetry and rotational symmetry for different objects Identify objects that have symmetrical properties

3. Vocabulary Line symmetry: Figures that match exactly when folded in half Rotational symmetry: Figures that line back up with itself when rotated 180 degrees or less around its center Transformation: Moving a figure without changing its size or shape Translation: Movement of a figure along a straight line Rotation: Movement of a figure around a point Reflection: When a figure flips over a line creating a mirror image

4. Questions Notes Questions Answers What is line symmetry? When folded in half, the figure will completely cover itself. Do all shapes have line symmetry? Some figures will have more than one line of symmetry, while others will have none. What is a line OF symmetry? The line that splits the shape When a shape fits ONTO itself two or more times in one full turn. The shape is rotated about a fixed point. What is rotational symmetry? This shape has 90 degree rotational symmetry because it fits onto itself 4 times, every 90o, in one rotation.

5. Which of the following figures have line symmetry?Draw the figures that have symmetry on your paper and add the lines of symmetry.

6. Is there symmetry in the Alphabet? • Find at least three letters of the alphabet that have only ONE vertical line of symmetry. • Find at least three letters of the alphabet that have only ONE horizontal line of symmetry. • Find the four letters that have both types of symmetry.

7. Symmetry in Nature

8. Symmetry in Art and Architecture

9. 1 1 __ __ 2 4 A full turn is a 360° rotation. So a turn is 90°, and a turn is 180°. How do you determine the degrees of rotational symmetry? 360° 90° 180° Where would 120° of rotational symmetry be? What about 270°? Or 45°?

10. Draw a 180° rotation about the point shown. Trace the figure and the point of rotation. Place your pencil on the point of rotation. Rotate the figure 180°. Trace the figure in its new location.

11. Which is true about the figure below? A. The figure has rotational symmetry after a 45° turn. B. The figure has rotational symmetry after 90 ° turn. C. The figure has rotational symmetry after a 120 ° turn. D. The figure does not have rotational symmetry.

12. When an object rotates it turns. So, rotational symmetry means turn symmetry. How many times can you turn the object below and it matches up with itself? What degree of rotational symmetry does it have?

13. Questions Notes Questions Answers What are the three types of transformations? Rotation, reflection, and translation What is a rotation? When a shape is rotated, or turned, around a central point. What is a reflection? When a shape is flipped to create a mirror image. What is a translation? When a shape slides over into a new place, but position stays the same.

14. A rotationis the movement of a figure around a point. A point of rotation can be on or outside a figure. The location and position of a figure can change with a rotation.

15. When a figure flips over a line, creating a mirror image, it is called a reflection. The line the figure is flipped over is called line of reflection. The location and position of a figure change with a reflection.

16. A translation is the movement of a figure along a straight line. Only the location of the figure changes with a translation.

17. Tell whether each is a translation, rotation, or reflection. The figure is flipped over a line. It is a reflection.

18. Tell whether each is a translation, rotation, or reflection. The figure moves around a point. It is a rotation.

19. Tell whether each is a translation, rotation, or reflection. The figure is moved along a line. It is a translation.

20. Objects with Rotational Symmetry